#21578E
Closest named color: Dusk Blue (#26538D). oklch(45% 0.107 251.8), rgb(33, 87, 142).
Aa
White text reads best on this color (7.45:1).
About this color
#21578E is a dark, moderately saturated blue. In OKLCH its lightness is 45%, its chroma 0.107 and its hue 252°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk Blue (#26538D), ΔE 0.011 away. White text reads best on it, at 7.45:1.
| Hue family | Blues |
| Lightness | dark (45%) |
| Chroma | moderately saturated (0.107) |
| Temperature | cool |
| Nearest name | Dusk Blue (#26538D) |
| Black text | 2.81:1 |
| White text | 7.45:1 |
Values
| HEX | #21578E |
| RGB | rgb(33, 87, 142) |
| HSL | hsl(210, 62%, 34%) |
| OKLCH | oklch(45% 0.107 251.8) |
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 #21578E | 7.45:1 | AAA | Lc -90.4 | Preferred for body text |
| Black text on #21578E | 2.81:1 | Fails | Lc 18.5 | Dividers and decoration only |
| #21578E text on white | 7.45:1 | AAA | Lc 85.6 | Fine for body text |
| #21578E text on black | 2.81:1 | Fails | Lc -16.5 | 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
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E1EBF6
oklch(93.6% 0.018 250.6)
-
Step 200
200
#C9DBF0
oklch(88.4% 0.035 252.3)
-
Step 300
300
#A4C4E8
oklch(80.9% 0.062 251.6)
-
Step 400
400
#71A5DD
oklch(70.8% 0.099 251.1)
-
Step 500
500
#4A8DD4
oklch(63.2% 0.127 251.7)
-
Step 600
600
#2A75C1
oklch(55.5% 0.139 252.1)
-
Step 700
700
#1B62A7
oklch(49% 0.13 252)
-
Step 800
800 (this color)
#21578E
oklch(45% 0.107 251.8)
-
Step 900
900
#1C436C
oklch(37.7% 0.083 251.9)
-
Step 950
950
#11283F
oklch(27.1% 0.052 250.3)
#21578E 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) | #3D5B90 | 0.031 |
| Deuteranopia (no green cones) | #2D508D | 0.021 |
| Tritanopia (no blue cones) | #00646B | 0.081 |
| Achromatopsia (no color) | #555555 | 0.107 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21578E
#21578E
oklch(45% 0.107 251.8)
- #764B00
#764B00
oklch(45.1% 0.097 71.9)
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 #21578E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk Blue #26538D ΔE 0.011
- Light Navy Blue #2E5A88 ΔE 0.019
- Light Navy #155084 ΔE 0.027
- Deep Sea Blue #015482 ΔE 0.028
- Denim Blue #3B5B92 ΔE 0.030
- Cobalt #1E488F ΔE 0.045
- Peacock Blue #016795 ΔE 0.046
- Denim #3B638C ΔE 0.047
Use #21578E 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.