Color television facts for kids
Color television lets us see pictures on TV screens in full color! Before color TV, all shows were in black and white, showing images in shades of gray. Color TV was a huge step forward in how we watch and enjoy programs.
Most TV stations around the world switched from black and white to color broadcasting between the 1960s and 1980s. This change was a big part of television's history and technological progress.
The idea of sending color pictures over long distances started way back in the 1880s. In 1928, John Logie Baird showed off a mechanical color TV system. But it wasn't until electronic systems were invented that color TV became truly practical.
Before World War II, black-and-white TV standards were set. But during the war, work on new electronics for everyday use paused. In August 1944, Baird showed the first fully electronic color TV screen. In the United States, different groups worked on color TV. They eventually created the NTSC color standard, which could even work with older black-and-white TVs.
The NTSC color standard was announced in 1953. But it took until the early 1970s for color TVs to sell more than black-and-white ones in North America. Europe adopted its own color standards, PAL or SECAM, in the 1960s.
Around 2006, many countries started switching from older analog color TV to newer, clearer digital television. This change is now complete in many places, but some countries still use analog TV.
How Color TV Works
Our eyes have special cells called rods and cones. Rods help us see in dim light. Cones help us see colors when it's bright enough. We have three types of cones, each sensitive to different colors: red, green, and blue.
When you watch a TV show, you see a series of still pictures shown very quickly. This makes them look like smooth, continuous motion. This trick works if about 16 pictures are shown every second. Most movies use 24 pictures per second.
Early TV systems showed 50 or 60 pictures (called "fields") per second. This speed matched the electricity in homes and helped avoid interference. Modern TVs can show different speeds and work with various electricity types.
Making Color Pictures
To create a color TV picture, you can combine three separate black-and-white images. One image shows the red parts, one the green, and one the blue. When these three images are shown together or very quickly, our eyes blend them into a full-color picture.
However, sending three separate images at once would use up a lot of radio space. This was a big challenge for early color TV inventors. They needed a way to send color information without using too much bandwidth.
In the United States, engineers at RCA found a clever solution. They created a system that separated the color information from the brightness information. The brightness part of the signal was like a regular black-and-white picture. This meant older black-and-white TVs could still show the picture, just without color.
Color TVs could then decode the extra color information. This system, called NTSC, was a major achievement. It allowed color TV to be compatible with older black-and-white sets.
Early Television Systems
The idea of sending images over radio waves started in the 1800s. But TV became practical only in the 1900s with new electronics. A big problem was turning a 2D image into a 1D radio signal. This needed a way to "scan" the image.
Early systems used a spinning disk with holes, called a "Nipkow disk". As the disk spun, a light sensor behind it captured the brightness of each tiny spot. This brightness was turned into a radio signal. A similar disk at the receiver side would then show the image.
John Logie Baird demonstrated one of the most famous mechanical TV systems in the 1920s. He even used it for public broadcasts in Britain. However, mechanical systems had problems. It was hard to keep the sending and receiving disks perfectly in sync. Also, larger, clearer pictures needed huge disks and made the images dim.
It became clear that electronic scanning would be much better. This led to inventions like Philo Farnsworth's electronic scanning system and Vladimir Zworykin's Iconoscope camera. These electronic systems made black-and-white TV broadcasts possible. The BBC started regular black-and-white TV in 1936.
First Color TV Experiments
People started experimenting with color TV almost as soon as black-and-white TV was invented. The basic idea was always to use three monochrome (black-and-white) images to create one color image.
In 1928, John Logie Baird showed the world's first color TV transmission. He used spinning disks with colored filters. Three light sources at the receiver, controlled by the signal, created the color image. He even broadcast color over the air in 1938.
Bell Laboratories also showed mechanical color TV in 1929. They used three separate systems for red, green, and blue, combining them with mirrors.
Mixing Old and New: Hybrid Systems
Electronic scanning was better than mechanical systems. For color cameras, three Iconoscope tubes with colored filters could capture red, green, and blue signals. A special lens system made sure all three tubes saw the same scene without distortion.
But how to show these three signals on a TV screen? One idea was to use three separate black-and-white screens, each with a colored filter. Mirrors or prisms would then combine these images onto a single screen. Radio Corporation of America (RCA) showed such a system in 1940. However, these TVs were very expensive and the pictures were quite dim.
Another idea was to use a single screen with tiny colored dots (phosphors) arranged in a pattern. Three electron guns would then aim at these dots, each hitting its specific color. But this technology was too advanced for the time.
So, inventors tried "hybrid" systems. These combined a regular black-and-white screen with a spinning colored disk or mirror. The three color images were sent one after another. A filter rotated in front of the screen in sync with the broadcast. This meant the TV had to show pictures much faster to avoid flicker, making it incompatible with existing black-and-white TVs.
In 1940, Baird publicly showed a color TV using a black-and-white screen and a rotating colored disk. Later, Peter Carl Goldmark at CBS developed a similar system. CBS even started experimental color broadcasts in 1940 and 1941. But these systems were not compatible with the millions of black-and-white TVs already in homes.
The Rise of Fully Electronic Color TV
Baird also worked on a fully electronic system called "Telechrome" in 1940. It used two electron guns and a special phosphor plate to create limited color images. His demonstration in 1944 was a big step for practical color TV.
Many similar ideas were explored in the 1940s and 1950s. These systems aimed to use multiple electron guns to light up colored phosphors on the screen.
Finding a Standard: FCC and Compatible Color
After World War II, many new TV stations wanted licenses. The Federal Communications Commission (FCC) paused new licenses to figure out how to manage the limited channels. They decided to use higher frequencies (UHF) for new TV broadcasts. Since no existing TVs could tune into these, they could choose a new, incompatible color system.
CBS showed improved versions of its mechanical system. But RCA was working on a "dot-sequential" system that could work with existing black-and-white TVs. This was called "compatible color." RCA believed this was the best solution.
In 1950, the FCC approved the CBS system. But by then, millions of black-and-white TVs were in use. Making them obsolete was no longer a good idea. RCA continued to develop its compatible color system, investing a lot of money.
A key invention was the shadow mask color TV, patented by Werner Flechsig in Germany in 1938. This system used a metal sheet with tiny holes. Three electron guns aimed at these holes from different angles. This made sure each gun hit only its specific colored dot (red, green, or blue) on the screen. Most color TVs today use this technology.
The NTSC Standard is Born
The idea of a compatible color system was so important that the National Television System Committee (NTSC) met again in 1950. They worked to create a color system that would work with black-and-white TVs and meet FCC standards. RCA developed the necessary hardware.
RCA started testing its dot-sequential color system in 1951. In 1953, the NTSC submitted its plan to the FCC, and it was approved on December 17, 1953. This became the official NTSC color standard for the U.S.
The first public network broadcast using the NTSC compatible color system was an episode of NBC's Kukla, Fran and Ollie in August 1953. The first network broadcast over the air in NTSC color was an opera called Carmen in October 1953.
Color TV Around the World
Even after color TV standards were set, it took time for people to buy color sets. They were expensive, and there wasn't much color programming at first.
North America
In the United States, the first national color broadcast was the 1954 Tournament of Roses Parade. But for many years, most shows were still in black and white. NBC, whose parent company RCA made color TVs, led the way in color programming. By the mid-1960s, color TV sales started to boom. In 1965, it was announced that over half of all prime-time shows would be in color that fall. By 1966, all three major networks had full color prime-time schedules. It wasn't until 1972 that color TV sales finally surpassed black-and-white sales.
Canada started official color broadcasts in 1966. By the late 1970s, most of the country had color TV.
Cuba introduced color TV broadcasting in 1958, using the American NTSC standard. However, these transmissions stopped in 1960 and didn't return until 1975.
In Mexico, Guillermo González Camarena invented his own color TV system in the late 1930s. He made the first public color broadcast in Mexico in 1964, using the NTSC system. NASA even used a modified version of his system for the Voyager mission to take pictures of Jupiter!
Europe
Europe saw its first color TV broadcasts in the mid-1960s. The United Kingdom's BBC2 and West Germany started regular color broadcasts in July and August 1967, using the PAL system. Many other Western European countries followed, adopting PAL in the late 1960s and 1970s.
France and most of Eastern Europe chose the SECAM system. SECAM was good for areas with many hills or older black-and-white equipment. However, editing SECAM video was more complex than PAL or NTSC.
Some British shows were filmed in color even before color TV came to the UK, so they could be sold to American networks. For example, The Adventures of Sir Lancelot (1956–57) and Stingray (1964–65) were made in color.
The last country in Europe to introduce color television was Romania in 1983.
Asia and the Pacific
Japan was the first country in Asia to introduce color television in 1960, using a version of the NTSC system. The Philippines and Taiwan also adopted NTSC.
Most other countries in the region used the PAL system. Australia started in 1974, followed by Thailand, Hong Kong, and the People's Republic of China in the late 1960s and 1970s. South Korea didn't introduce color TV until 1980–81, even though it was already making color TVs for export.
The People's Republic of China began testing color TV in 1970 and adopted PAL in 1971. Regular full-time color broadcasts started in 1973.
The last country in Asia and the world to introduce color television was Cambodia in 1986.
Middle East
Most countries in the Middle East use PAL. Lebanon was the first to introduce color TV in 1967. Jordan, Iraq, and Oman followed in the early 1970s. Saudi Arabia, the United Arab Emirates, and others adopted it in the mid-1970s. Israel continued to broadcast mostly in black and white until the early 1980s.
Africa
The first color TV service in Africa was on the Tanzanian island of Zanzibar in 1973, using NTSC. Mauritius also broadcast in color in 1973 using SECAM. South Africa launched its TV service, in color, in 1976. Nigeria adopted PAL for color in 1975.
The last country in Africa to introduce color television was Ghana in 1985.
South America
Most South American countries adopted NTSC, but Brazil started broadcasting in color using PAL-M in 1972. Ecuador was the first South American country to use NTSC color in 1974.
Argentina started international color broadcasting for the 1978 FIFA World Cup using PAL-B. Domestic color broadcasting became regular in 1980 using PAL-N. Chile officially adopted NTSC color in 1978.
Some other countries like Bolivia, Paraguay, Peru, and Uruguay didn't have full-time color TV until the early 1980s.
Color TV Standards Around the World
There are three main analog color TV systems used globally:
- NTSC (National Television Standards Committee)
- PAL (Phase Alternating Line)
- SECAM (Séquentiel Couleur à Mémoire—Sequential Color with Memory)
NTSC is used in North and South America (except Brazil and Argentina), and parts of Asia like Japan. Most of Asia, Western Europe, Australia, Africa, and Eastern South America use PAL. Eastern Europe and France use SECAM.
These systems are different, so a TV designed for one standard usually can't display video from another without a special converter.
This table shows some of the differences between these systems:
| NTSC M | PAL B,G,H | PAL I | PAL N | PAL M | SECAM B,G,H | SECAM D,K,K' | SECAM L | |
|---|---|---|---|---|---|---|---|---|
| Lines/Fields | 525/60 | 625/50 | 625/50 | 625/50 | 525/60 | 625/50 | 625/50 | 625/50 |
| Horizontal Frequency | 15.734 kHz | 15.625 kHz | 15.625 kHz | 15.625 kHz | 15.750 kHz | 15.625 kHz | 15.625 kHz | 15.625 kHz |
| Vertical Frequency | 60 Hz | 50 Hz | 50 Hz | 50 Hz | 60 Hz | 50 Hz | 50 Hz | 50 Hz |
| Color Subcarrier Frequency | 3.579545 MHz | 4.43361875 MHz | 4.43361875 MHz | 3.582056 MHz | 3.575611 MHz | 4.25000/4.40625 MHz[1] | 4.25000/4.40625 MHz[1] | 4.25000/4.40625 MHz[1] |
| Video Bandwidth | 4.2 MHz | 5.0 MHz | 5.5 MHz | 4.2 MHz | 4.2 MHz | 5.0 MHz | 6.0 MHz | 6.0 MHz |
| Sound Carrier | 4.5 MHz | 5.5 MHz | 5.9996 MHz | 4.5 MHz | 4.5 MHz | 5.5 MHz | 6.5 MHz | 6.5 MHz |
| Video Modulation | Negative | Negative | Negative | Negative | Negative | Negative | Negative | Positive |
For SECAM, the color signal changes frequencies for different color information. This is different from PAL and NTSC, which use phase changes.
Today, many countries have switched to digital television standards like ATSC, DVB-T, and ISDB. These newer systems have replaced the older analog color TV standards.
See also
In Spanish: Televisión en color para niños
- Beam-index tube
- Triniscope
