#21559B
Closest named color: Dusk Blue (#26538D). oklch(45.4% 0.127 257), rgb(33, 85, 155).
Aa
White text reads best on this color (7.40:1).
About this color
#21559B is a medium-dark, moderately saturated blue. In OKLCH its lightness is 45%, its chroma 0.127 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk Blue (#26538D), ΔE 0.023 away. White text reads best on it, at 7.40:1.
| Hue family | Blues |
| Lightness | medium-dark (45%) |
| Chroma | moderately saturated (0.127) |
| Temperature | cool |
| Nearest name | Dusk Blue (#26538D) |
| Black text | 2.83:1 |
| White text | 7.40:1 |
Values
| HEX | #21559B |
| RGB | rgb(33, 85, 155) |
| HSL | hsl(214, 65%, 37%) |
| OKLCH | oklch(45.4% 0.127 257) |
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 #21559B | 7.40:1 | AAA | Lc -90.2 | Preferred for body text |
| Black text on #21559B | 2.83:1 | Fails | Lc 18.7 | Dividers and decoration only |
| #21559B text on white | 7.40:1 | AAA | Lc 85.3 | Fine for body text |
| #21559B text on black | 2.83:1 | Fails | Lc -16.7 | Dividers and decoration only |
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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF9
oklch(93.7% 0.022 256.7)
-
Step 200
200
#C8DBF5
oklch(88.5% 0.041 256.2)
-
Step 300
300
#A2C3F1
oklch(80.9% 0.075 256.7)
-
Step 400
400
#70A2EA
oklch(70.7% 0.119 257.5)
-
Step 500
500
#4889E3
oklch(63.1% 0.152 257.1)
-
Step 600
600
#2871D1
oklch(55.6% 0.165 257)
-
Step 700
700
#1A5EB5
oklch(49.1% 0.153 256.9)
-
Step 800
800 (this color)
#21559B
oklch(45.4% 0.127 257)
-
Step 900
900
#1B4175
oklch(37.7% 0.099 257.1)
-
Step 950
950
#112644
oklch(26.9% 0.062 257.5)
#21559B 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) | #315B9E | 0.024 |
| Deuteranopia (no green cones) | #18509A | 0.017 |
| Tritanopia (no blue cones) | #006670 | 0.099 |
| Achromatopsia (no color) | #555555 | 0.127 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21559B
#21559B
oklch(45.4% 0.127 257)
- #734E00
#734E00
oklch(45.3% 0.095 77.4)
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 #21559B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk Blue #26538D ΔE 0.023
- Denim Blue #3B5B92 ΔE 0.036
- Light Navy Blue #2E5A88 ΔE 0.039
- Cobalt #1E488F ΔE 0.040
- Light Navy #155084 ΔE 0.041
- Deep Sea Blue #015482 ΔE 0.046
- Dusky Blue #475F94 ΔE 0.054
- Twilight #4E518B ΔE 0.055
Use #21559B 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.