#21555B
Closest named color: Deep Teal (#00555A). oklch(41.7% 0.056 205.6), rgb(33, 85, 91).
Aa
White text reads best on this color (8.34:1).
About this color
#21555B is a dark, muted teal or cyan. In OKLCH its lightness is 42%, its chroma 0.056 and its hue 206°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Teal (#00555A), ΔE 0.017 away. White text reads best on it, at 8.34:1.
| Hue family | Teals and cyans |
| Lightness | dark (42%) |
| Chroma | muted (0.056) |
| Temperature | cool |
| Nearest name | Deep Teal (#00555A) |
| Black text | 2.51:1 |
| White text | 8.34:1 |
Values
| HEX | #21555B |
| RGB | rgb(33, 85, 91) |
| HSL | hsl(186, 47%, 24%) |
| OKLCH | oklch(41.7% 0.056 205.6) |
Contrast
WCAG 2 contrast ratios are the conformance target: AA needs 4.5:1 for body text and 3:1 for large text, AAA needs 7:1. APCA Lc values are supplementary guidance from the WCAG 3 drafts.
| Pair | WCAG 2 | Result | APCA | APCA guidance |
|---|---|---|---|---|
| White text on #21555B | 8.34:1 | AAA | Lc -93.2 | Preferred for body text |
| Black text on #21555B | 2.51:1 | Fails | Lc 15.4 | Dividers and decoration only |
| #21555B text on white | 8.34:1 | AAA | Lc 88.6 | Fine for body text |
| #21555B text on black | 2.51:1 | Fails | Lc -13.6 | Not readable |
Tints and shades
A 50–950 scale built in OKLCH: the hue is held, lightness follows a Tailwind v4-like curve, and every step is kept inside the sRGB gamut. This color sits at step 800.
-
Step 50
50
#F2F6F7
oklch(97% 0.004 214.3)
-
Step 100
100
#E3ECED
oklch(93.7% 0.01 204.9)
-
Step 200
200
#CCDDDF
oklch(88.5% 0.018 205.3)
-
Step 300
300
#A9C7CB
oklch(80.9% 0.033 206.4)
-
Step 400
400
#7AAAB0
oklch(70.6% 0.052 205.7)
-
Step 500
500
#56959D
oklch(63.1% 0.066 206.1)
-
Step 600
600
#387F88
oklch(55.5% 0.072 206.5)
-
Step 700
700
#296C73
oklch(49.2% 0.067 204.8)
-
Step 800
800 (this color)
#21555B
oklch(41.7% 0.056 205.6)
-
Step 900
900
#23484D
oklch(37.6% 0.043 206.9)
-
Step 950
950
#152A2D
oklch(26.9% 0.027 207.4)
#21555B with color blindness
Simulated with the Machado et al. (2009) model. ΔE is how far the color moves: below about 0.02 you would not notice a change.
| Vision | Seen as | Shift (ΔE) |
|---|---|---|
| Protanopia (no red cones) | #4E525B | 0.054 |
| Deuteranopia (no green cones) | #454B5B | 0.050 |
| Tritanopia (no blue cones) | #005957 | 0.022 |
| Achromatopsia (no color) | #4E4E4E | 0.056 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21555B
#21555B
oklch(41.7% 0.056 205.6)
- #67403D
#67403D
oklch(41.6% 0.055 24.5)
Analogous
Neighbouring hues, 30° either side.
Split complementary
The two hues beside the complement (150° and 210°).
Triadic
Three hues spaced 120° apart.
Palettes with this color
Curated palettes that contain a color within ΔE 0.04 (OKLab) of #21555B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Teal #00555A ΔE 0.017
- Dark Slate Gray #2F4F4F ΔE 0.024
- Petrol #005F6A ΔE 0.034
- Dark Blue Green #005249 ΔE 0.038
- Dark Teal #014D4E ΔE 0.039
- Charcoal #264653 ΔE 0.047
- Dark Green Blue #1F6357 ΔE 0.049
- Dark Grey Blue #29465B ΔE 0.049
Use #21555B in your product
Turn it into light and dark UI roles checked for contrast, then export to Tailwind v4, shadcn/ui, CSS or design tokens.