#21375D
Closest named color: Prussian Blue (#1D3557). oklch(33.9% 0.073 260.7), rgb(33, 55, 93).
Aa
White text reads best on this color (11.86:1).
About this color
#21375D is a dark, moderately saturated blue. In OKLCH its lightness is 34%, its chroma 0.073 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.013 away. White text reads best on it, at 11.86:1.
| Hue family | Blues |
| Lightness | dark (34%) |
| Chroma | moderately saturated (0.073) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.76:1 |
| White text | 11.86:1 |
Values
| HEX | #21375D |
| RGB | rgb(33, 55, 93) |
| HSL | hsl(218, 48%, 25%) |
| OKLCH | oklch(33.9% 0.073 260.7) |
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 #21375D | 11.86:1 | AAA | Lc -100.7 | Preferred for body text |
| Black text on #21375D | 1.76:1 | Fails | Lc 0.0 | Not readable |
| #21375D text on white | 11.86:1 | AAA | Lc 97.1 | Preferred for body text |
| #21375D text on black | 1.76:1 | Fails | Lc 0.0 | 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 900.
-
Step 50
50
#F3F6FA
oklch(97.2% 0.006 255.5)
-
Step 100
100
#E4EAF5
oklch(93.6% 0.016 262.8)
-
Step 200
200
#CEDAEE
oklch(88.5% 0.03 260.7)
-
Step 300
300
#ADC2E5
oklch(81% 0.055 260.6)
-
Step 400
400
#81A1D7
oklch(70.6% 0.087 260.7)
-
Step 500
500
#6289CD
oklch(63.1% 0.112 261)
-
Step 600
600
#4972BA
oklch(55.6% 0.122 260.9)
-
Step 700
700
#3A5FA0
oklch(49% 0.113 260.9)
-
Step 800
800
#304E82
oklch(42.7% 0.094 260.7)
-
Step 900
900 (this color)
#21375D
oklch(33.9% 0.073 260.7)
-
Step 950
950
#19263D
oklch(26.9% 0.047 261.3)
#21375D 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) | #273A5F | 0.013 |
| Deuteranopia (no green cones) | #1F355C | 0.007 |
| Tritanopia (no blue cones) | #004045 | 0.064 |
| Achromatopsia (no color) | #373737 | 0.073 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21375D
#21375D
oklch(33.9% 0.073 260.7)
- #4A3300
#4A3300
oklch(33.9% 0.07 80.9)
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 #21375D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.013
- Marine Blue #01386A ΔE 0.031
- Dark Blue Grey #1F3B4D ΔE 0.035
- Marine #042E60 ΔE 0.042
- Midnight Green #073B4C ΔE 0.043
- Gunmetal #293241 ΔE 0.049
- Space Cadet #2B2D42 ΔE 0.052
- Dark Grey Blue #29465B ΔE 0.052
Use #21375D 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.