#0051A9
Closest named color: Cobalt (#1E488F). oklch(44.8% 0.157 256.6), rgb(0, 81, 169).
Aa
White text reads best on this color (7.63:1).
About this color
#0051A9 is a dark, vivid blue. In OKLCH its lightness is 45%, its chroma 0.157 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.047 away. White text reads best on it, at 7.63:1.
| Hue family | Blues |
| Lightness | dark (45%) |
| Chroma | vivid (0.157) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.74:1 |
| White text | 7.63:1 |
Values
| HEX | #0051A9 |
| RGB | rgb(0, 81, 169) |
| HSL | hsl(211, 100%, 33%) |
| OKLCH | oklch(44.8% 0.157 256.6) |
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 #0051A9 | 7.63:1 | AAA | Lc -90.6 | Preferred for body text |
| Black text on #0051A9 | 2.74:1 | Fails | Lc 18.3 | Dividers and decoration only |
| #0051A9 text on white | 7.63:1 | AAA | Lc 85.8 | Fine for body text |
| #0051A9 text on black | 2.74:1 | Fails | Lc -16.3 | 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
#F0F6FE
oklch(97.1% 0.012 255.5)
-
Step 100
100
#DFEBFC
oklch(93.6% 0.026 257)
-
Step 200
200
#C4DBFB
oklch(88.5% 0.051 256.7)
-
Step 300
300
#9AC3FC
oklch(80.9% 0.092 256.7)
-
Step 400
400
#61A2FA
oklch(70.8% 0.146 256.4)
-
Step 500
500
#2F87F8
oklch(63.1% 0.188 256.7)
-
Step 600
600
#006EE1
oklch(55.5% 0.194 256.7)
-
Step 700
700
#005CBF
oklch(49% 0.172 256.8)
-
Step 800
800 (this color)
#0051A9
oklch(44.8% 0.157 256.6)
-
Step 900
900
#093F80
oklch(37.6% 0.122 256.6)
-
Step 950
950
#09264B
oklch(27.1% 0.077 256.3)
#0051A9 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) | #105BAC | 0.029 |
| Deuteranopia (no green cones) | #004DA7 | 0.011 |
| Tritanopia (no blue cones) | #006775 | 0.118 |
| Achromatopsia (no color) | #535353 | 0.157 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #0051A9
#0051A9
oklch(44.8% 0.157 256.6)
- #724C00
#724C00
oklch(44.8% 0.094 75.9)
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 #0051A9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.047
- Dusk Blue #26538D ΔE 0.050
- Sapphire #2138AB ΔE 0.060
- Blue Blue #2242C7 ΔE 0.060
- Light Navy #155084 ΔE 0.060
- Denim Blue #3B5B92 ΔE 0.065
- Deep Sea Blue #015482 ΔE 0.066
- Light Navy Blue #2E5A88 ΔE 0.069
Use #0051A9 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.