Color Converter

Most of the formats here describe the same thing in different words. HEX is RGB written in base sixteen, so the three pairs of digits are red, green, and blue channel values from 0 to 255. The three-character shorthand expands by repeating each digit, which is why it can only express colors whose channel pairs happen to be doubled. A fourth pair when present carries alpha.

HSL and HSV aren't the same model

Both rearrange RGB into a cylinder with hue as the angle, and they are easy to confuse because the first two components share names. The difference is at the top of the range. In HSL, lightness at one hundred percent is always white and a pure vivid hue sits at fifty percent. In HSV, value at one hundred percent with full saturation gives the pure hue itself, and white requires dropping saturation to zero. Copying an S and L value into a tool expecting S and V therefore produces a visibly different color.

CMYK conversion has no single correct answer

This is the conversion that surprises people. RGB describes light emitted by a screen and CMYK describes ink absorbed on paper, and the translation between them depends on the specific press, ink set, and paper stock. Without an accompanying color profile, any CMYK figure is an approximation using a generic assumption. Vivid screen colors, particularly bright cyans, oranges, and pure greens, fall outside what process inks can reproduce at all. So the conversion returns the nearest printable color rather than a match. Anything going to a commercial printer should be converted using the profile that printer supplies.

Rounding drift on round trips

Converting from RGB to HSL and back can return a value one or two units away from where it started, because HSL components are usually expressed as rounded percentages and integer degrees. The drift is invisible to the eye but will break an exact string comparison, so treat the original notation as canonical rather than converting back and forth in a pipeline.

Newer CSS color notations are worth knowing about if you're working on the web. Formats such as OKLCH describe color in perceptually uniform terms, which makes generating consistent tints and shades far more predictable than nudging HSL values, and wide-gamut notations can express colors that simply have no sRGB equivalent.