ColrShift212121 — RGB, HSL, CMYK and Contrast
A neutral at 13% lightness and 0% saturation, which puts it at 16.10:1 against white and 1.30:1 against black. The tables below give the notation conversions, the tints and shades that keep the hue intact, and the harmonies that pair with it.
Notation conversions
| Notation | Value |
|---|---|
| HEX | 212121 |
| RGB | rgb(33, 33, 33) |
| HSL | hsl(0, 0%, 13%) |
| CMYK | cmyk(0%, 0%, 0%, 87%) |
| Relative luminance | 0.0152 |
| Perceived brightness | 12.9 / 100 |
Contrast against pure white and pure black
Pair this colour with the two extremes to see which is the safer text partner. AA needs 4.5:1 for body text and 3:1 for large text; AAA raises that to 7:1 and 4.5:1.
| Against | Hex | Ratio | AA text | AA large | AAA text |
|---|---|---|---|---|---|
| #FFFFFF | white | 16.10:1 | pass | pass | pass |
| #000000 | black | 1.30:1 | fail | fail | fail |
Tints and shades
Lightness moves in ten-point steps while hue and saturation stay fixed, which keeps the colour recognisable in a scale. The last column is the ratio against white text, useful for deciding where a scale stops working as a background.
| Step | Hex | HSL | vs white text |
|---|---|---|---|
| shade -30 | #000000 | hsl(0, 0%, 0%) | 21.00:1 |
| shade -20 | #000000 | hsl(0, 0%, 0%) | 21.00:1 |
| shade -10 | #080808 | hsl(0, 0%, 3%) | 20.03:1 |
| tint +10 | #3b3b3b | hsl(0, 0%, 23%) | 11.20:1 |
| tint +20 | #545454 | hsl(0, 0%, 33%) | 7.57:1 |
| tint +30 | #6e6e6e | hsl(0, 0%, 43%) | 5.10:1 |
Harmonies
| Scheme | Hex |
|---|---|
| Complementary | #212121 |
| Analogous −30 | #212121 |
| Analogous +30 | #212121 |
| Triadic −120 | #212121 |
| Triadic +120 | #212121 |
Take the channels apart and the numbers hold together: 33, 33 and 33 average 33, the strongest channel is 33 and the weakest 33, and that span is what pushes saturation to 0.0% at hue 0.0° and lightness 12.9%. Luminance 0.0152 with perceived brightness 12.9 out of 100 is why the white ratio (16.10:1) and the black ratio (1.30:1) diverge by 14.80. Entry 58 of 69, it steps to #000000 at minus thirty and #6e6e6e at plus thirty.
Nearby colours
Frequently asked questions
What text colour should sit on 212121?
Black gives 1.30:1 and white gives 16.10:1, so white wins at 16.10:1. That clears the 4.5:1 AA threshold for normal text and the 7:1 AAA threshold as well.
Do the CMYK numbers match a print workflow?
They are the naive conversion from RGB, which assumes no ink limit, no colour profile and no black generation strategy. Real print work needs a profile-aware conversion; the values here are the ones the converter reports and are best used as a starting point for a designer rather than a press-ready separations file.
Convert any other colour, or test a pair against each other, in the ColrShift colour converter and contrast checker. The colour library groups every entry on this site by hue family.