#00557B
Closest named color: Deep Sea Blue (#015482). oklch(42.6% 0.093 237.2), rgb(0, 85, 123).
Aa
White text reads best on this color (8.12:1).
About this color
#00557B is a dark, moderately saturated blue. In OKLCH its lightness is 43%, its chroma 0.093 and its hue 237°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sea Blue (#015482), ΔE 0.013 away. White text reads best on it, at 8.12:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | moderately saturated (0.093) |
| Temperature | cool |
| Nearest name | Deep Sea Blue (#015482) |
| Black text | 2.58:1 |
| White text | 8.12:1 |
Values
| HEX | #00557B |
| RGB | rgb(0, 85, 123) |
| HSL | hsl(199, 100%, 24%) |
| OKLCH | oklch(42.6% 0.093 237.2) |
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 #00557B | 8.12:1 | AAA | Lc -92.3 | Preferred for body text |
| Black text on #00557B | 2.58:1 | Fails | Lc 16.4 | Dividers and decoration only |
| #00557B text on white | 8.12:1 | AAA | Lc 87.6 | Fine for body text |
| #00557B text on black | 2.58:1 | Fails | Lc -14.6 | 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 800.
-
Step 50
50
#F1F6FA
oklch(97.1% 0.008 241.7)
-
Step 100
100
#E1ECF3
oklch(93.7% 0.015 235.4)
-
Step 200
200
#C7DDEB
oklch(88.6% 0.03 235.7)
-
Step 300
300
#A0C7E0
oklch(81% 0.055 236.5)
-
Step 400
400
#6AA9D0
oklch(70.7% 0.087 236.9)
-
Step 500
500
#3B93C4
oklch(63.2% 0.111 236.8)
-
Step 600
600
#027CB1
oklch(55.6% 0.121 237.3)
-
Step 700
700
#006896
oklch(49.1% 0.108 237.6)
-
Step 800
800 (this color)
#00557B
oklch(42.6% 0.093 237.2)
-
Step 900
900
#114763
oklch(37.8% 0.072 236.5)
-
Step 950
950
#0D2A3A
oklch(27.1% 0.045 236.1)
#00557B 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) | #42557D | 0.051 |
| Deuteranopia (no green cones) | #334B7A | 0.041 |
| Tritanopia (no blue cones) | #005F62 | 0.060 |
| Achromatopsia (no color) | #505050 | 0.093 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #00557B
#00557B
oklch(42.6% 0.093 237.2)
- #743F10
#743F10
oklch(42.5% 0.094 56.7)
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 #00557B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sea Blue #015482 ΔE 0.013
- Light Navy #155084 ΔE 0.025
- Dusk Blue #26538D ΔE 0.039
- Light Navy Blue #2E5A88 ΔE 0.040
- Petrol #005F6A ΔE 0.049
- YInMn Blue #415A77 ΔE 0.054
- Twilight Blue #0A437A ΔE 0.055
- Cobalt #1E488F ΔE 0.056
Use #00557B 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.