#21557D
Closest named color: Deep Sea Blue (#015482). oklch(43.4% 0.086 245), rgb(33, 85, 125).
Aa
White text reads best on this color (7.89:1).
About this color
#21557D is a dark, moderately saturated blue. In OKLCH its lightness is 43%, its chroma 0.086 and its hue 245°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sea Blue (#015482), ΔE 0.018 away. White text reads best on it, at 7.89:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | moderately saturated (0.086) |
| Temperature | cool |
| Nearest name | Deep Sea Blue (#015482) |
| Black text | 2.66:1 |
| White text | 7.89:1 |
Values
| HEX | #21557D |
| RGB | rgb(33, 85, 125) |
| HSL | hsl(206, 58%, 31%) |
| OKLCH | oklch(43.4% 0.086 245) |
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 #21557D | 7.89:1 | AAA | Lc -91.9 | Preferred for body text |
| Black text on #21557D | 2.66:1 | Fails | Lc 16.9 | Dividers and decoration only |
| #21557D text on white | 7.89:1 | AAA | Lc 87.1 | Fine for body text |
| #21557D text on black | 2.66:1 | Fails | Lc -15.0 | 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
#F2F6FA
oklch(97.1% 0.007 247.9)
-
Step 100
100
#E2EBF3
oklch(93.6% 0.015 244.7)
-
Step 200
200
#CADCEB
oklch(88.6% 0.028 243.1)
-
Step 300
300
#A6C5E0
oklch(81% 0.051 244.8)
-
Step 400
400
#75A6D0
oklch(70.6% 0.081 245.2)
-
Step 500
500
#4F8FC4
oklch(63% 0.104 245.5)
-
Step 600
600
#3079B0
oklch(55.6% 0.112 244.7)
-
Step 700
700
#226597
oklch(49% 0.104 245.1)
-
Step 800
800 (this color)
#21557D
oklch(43.4% 0.086 245)
-
Step 900
900
#1F4563
oklch(37.8% 0.067 244.8)
-
Step 950
950
#13283A
oklch(26.9% 0.043 246.2)
#21557D 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) | #43567F | 0.037 |
| Deuteranopia (no green cones) | #364D7C | 0.029 |
| Tritanopia (no blue cones) | #005F63 | 0.063 |
| Achromatopsia (no color) | #515151 | 0.086 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21557D
#21557D
oklch(43.4% 0.086 245)
- #714614
#714614
oklch(43.5% 0.086 65.3)
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 #21557D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sea Blue #015482 ΔE 0.018
- Light Navy #155084 ΔE 0.023
- Light Navy Blue #2E5A88 ΔE 0.026
- Dusk Blue #26538D ΔE 0.029
- YInMn Blue #415A77 ΔE 0.040
- Denim Blue #3B5B92 ΔE 0.047
- Petrol #005F6A ΔE 0.053
- Dusk #4E5481 ΔE 0.053
Use #21557D 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.