Index
Colour Converters
Eight converters, each with the formula written out and a worked example. Everything runs in your browser — no colour you enter is sent anywhere.
Which one do you need? #
The choice usually comes down to what you are about to do with the colour.
- Sending something to print. Start with HEX to CMYK or RGB to CMYK, then read why print never matches your screen before you approve anything.
- Bringing a print colour onto the web. CMYK to HEX, then check the result on more than one screen.
- Writing CSS. HEX to HSL. Keeping colours in HSL makes light and dark variants far easier to maintain.
- Reading someone else's code. HEX to RGB or RGB to HEX, depending on which direction you are going.
What these tools do differently #
Most converters give you a number and stop. Each page here also shows the formula it used, one example worked through by hand, and the specific thing that formula gets wrong. That last part matters more than it sounds: the plain arithmetic behind RGB to CMYK, for instance, assumes ink behaves like a perfect filter, and it does not.
Every page also reports total ink coverage, which is the figure that decides whether a colour can actually be printed rather than just calculated.
Still being built #
This is a new site and we are adding converters as we can write them properly, rather than publishing thirty thin pages at once. Coming next: HSV, LAB, RGBA and 8-digit hex with alpha. If there is one you need, tell us and it will move up the list.