Color models are systems for describing and mixing colors in art, design, photography, web design, and printing. This cheat sheet helps students choose the right model for screens, printed projects, and digital design tools. It gives quick meanings for RGB, CMYK, HSL, and HEX so students can read color settings with confidence.
Knowing these models makes it easier to match colors, adjust designs, and avoid output problems.
Key Facts
- RGB is an additive color model for screens, and each channel usually ranges from 0 to 255, such as RGB(255, 0, 0) for red.
- In RGB, black is RGB(0, 0, 0) because no light is emitted, and white is RGB(255, 255, 255) because red, green, and blue light are all at full strength.
- CMYK is a subtractive color model for printing, and each ink channel is usually written as a percentage from 0% to 100%.
- In CMYK, pure white is usually CMYK(0%, 0%, 0%, 0%) because no ink is printed on white paper.
- HSL describes color using hue, saturation, and lightness, written as HSL(hue, saturation%, lightness%), such as HSL(120, 100%, 50%) for bright green.
- Hue is measured on a 0 to 360 degree color wheel, where 0 or 360 is red, 120 is green, and 240 is blue.
- HEX color codes are six-digit web color values written as #RRGGBB, where each pair controls red, green, and blue from 00 to FF.
- The HEX code #000000 means black, #FFFFFF means white, #FF0000 means red, #00FF00 means green, and #0000FF means blue.
Vocabulary
- RGB
- RGB is a screen color model that mixes red, green, and blue light to create colors.
- CMYK
- CMYK is a print color model that uses cyan, magenta, yellow, and black inks to create colors on paper.
- HSL
- HSL is a color model that describes a color by its hue, saturation, and lightness.
- HEX code
- A HEX code is a six-character RGB color value used in digital design and web pages.
- Saturation
- Saturation describes how intense or gray a color appears, from dull to vivid.
- Gamut
- A gamut is the range of colors a device, screen, printer, or color model can produce.
Common Mistakes to Avoid
- Using RGB for final print files is a mistake because RGB is made for light on screens, while printers use ink and may shift colors during conversion.
- Reading HEX values as normal decimal numbers is wrong because HEX uses base 16, where A through F represent values 10 through 15.
- Confusing saturation with lightness is a mistake because saturation controls color intensity, while lightness controls how close a color is to black or white.
- Expecting printed colors to exactly match screen colors is wrong because monitors emit light, paper reflects light, and each device has a different color gamut.
- Forgetting the percent signs in CMYK and HSL settings can cause confusion because CMYK ink amounts, HSL saturation, and HSL lightness are normally written as percentages.
Practice Questions
- 1 Write the RGB value for pure blue using 0 to 255 channel values.
- 2 What color is represented by the HEX code #00FF00?
- 3 In HSL(30, 100%, 50%), identify the hue, saturation, and lightness values.
- 4 A student designs a poster in bright RGB colors for a school print project. Explain why the printed poster might look less vivid than the screen version.