#51639F
Closest named color: Dusky Blue (#475F94). oklch(51.3% 0.098 270), rgb(81, 99, 159).
Aa
White text reads best on this color (5.77:1).
About this color
#51639F is a medium-dark, moderately saturated blue. In OKLCH its lightness is 51%, its chroma 0.098 and its hue 270°. Its hue sits on the cool side of the wheel. The nearest named color is Dusky Blue (#475F94), ΔE 0.025 away. White text reads best on it, at 5.77:1.
| Hue family | Blues |
| Lightness | medium-dark (51%) |
| Chroma | moderately saturated (0.098) |
| Temperature | cool |
| Nearest name | Dusky Blue (#475F94) |
| Black text | 3.63:1 |
| White text | 5.77:1 |
Values
| HEX | #51639F |
| RGB | rgb(81, 99, 159) |
| HSL | hsl(226, 33%, 47%) |
| OKLCH | oklch(51.3% 0.098 270) |
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 #51639F | 5.77:1 | AA | Lc -84.0 | Fine for body text |
| Black text on #51639F | 3.63:1 | AA large text | Lc 25.3 | Dividers and decoration only |
| #51639F text on white | 5.77:1 | AA | Lc 78.8 | Fine for body text |
| #51639F text on black | 3.63:1 | AA large text | Lc -23.0 | 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 700.
-
Step 50
50
#F4F5FA
oklch(97.1% 0.007 277.2)
-
Step 100
100
#E6EAF3
oklch(93.7% 0.013 266.7)
-
Step 200
200
#D2D9EB
oklch(88.5% 0.026 268.8)
-
Step 300
300
#B4C0E0
oklch(80.9% 0.047 269.1)
-
Step 400
400
#8E9FD1
oklch(70.8% 0.076 269.9)
-
Step 500
500
#7386C4
oklch(63% 0.096 270.5)
-
Step 600
600
#5B6FB1
oklch(55.5% 0.106 269.9)
-
Step 700
700 (this color)
#51639F
oklch(51.3% 0.098 270)
-
Step 800
800
#3E4C7B
oklch(42.7% 0.08 270.2)
-
Step 900
900
#344063
oklch(37.8% 0.062 268.9)
-
Step 950
950
#1F253A
oklch(26.9% 0.04 271.3)
#51639F 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) | #4C69A1 | 0.017 |
| Deuteranopia (no green cones) | #44629E | 0.017 |
| Tritanopia (no blue cones) | #327079 | 0.089 |
| Achromatopsia (no color) | #666666 | 0.098 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51639F
#51639F
oklch(51.3% 0.098 270)
- #7D6413
#7D6413
oklch(51.4% 0.098 90.1)
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 #51639F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusky Blue #475F94 ΔE 0.025
- French Blue #436BAD ΔE 0.030
- Denim #3B638C ΔE 0.042
- Denim Blue #3B5B92 ΔE 0.042
- Muted Blue #3B719F ΔE 0.044
- Flat Blue #3C73A8 ΔE 0.047
- Mid Blue #276AB3 ΔE 0.049
- Dull Blue #49759C ΔE 0.053
Use #51639F 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.