#1B557F
Closest named color: Deep Sea Blue (#015482). oklch(43.4% 0.091 244.4), rgb(27, 85, 127).
Aa
White text reads best on this color (7.91:1).
About this color
#1B557F is a dark, moderately saturated blue. In OKLCH its lightness is 43%, its chroma 0.091 and its hue 244°. 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 7.91:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | moderately saturated (0.091) |
| Temperature | cool |
| Nearest name | Deep Sea Blue (#015482) |
| Black text | 2.65:1 |
| White text | 7.91:1 |
Values
| HEX | #1B557F |
| RGB | rgb(27, 85, 127) |
| HSL | hsl(205, 65%, 30%) |
| OKLCH | oklch(43.4% 0.091 244.4) |
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 #1B557F | 7.91:1 | AAA | Lc -91.9 | Preferred for body text |
| Black text on #1B557F | 2.65:1 | Fails | Lc 16.9 | Dividers and decoration only |
| #1B557F text on white | 7.91:1 | AAA | Lc 87.1 | Fine for body text |
| #1B557F text on black | 2.65:1 | Fails | Lc -15.0 | 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 800.
-
Step 50
50
#F2F6FA
oklch(97.1% 0.007 247.9)
-
Step 100
100
#E2EBF4
oklch(93.6% 0.016 248)
-
Step 200
200
#C9DCEC
oklch(88.5% 0.03 243.4)
-
Step 300
300
#A4C5E1
oklch(80.9% 0.053 244.1)
-
Step 400
400
#72A7D2
oklch(70.8% 0.085 243.9)
-
Step 500
500
#4A90C7
oklch(63.2% 0.109 244.5)
-
Step 600
600
#2879B3
oklch(55.6% 0.118 244.4)
-
Step 700
700
#1A669A
oklch(49.2% 0.109 244.2)
-
Step 800
800 (this color)
#1B557F
oklch(43.4% 0.091 244.4)
-
Step 900
900
#1C4564
oklch(37.7% 0.07 244.2)
-
Step 950
950
#11293B
oklch(27.1% 0.045 243.2)
#1B557F 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) | #425681 | 0.040 |
| Deuteranopia (no green cones) | #344D7E | 0.030 |
| Tritanopia (no blue cones) | #005F64 | 0.064 |
| Achromatopsia (no color) | #515151 | 0.091 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B557F
#1B557F
oklch(43.4% 0.091 244.4)
- #73440D
#73440D
oklch(43.3% 0.091 63.7)
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 #1B557F, 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 0.020
- Dusk Blue #26538D ΔE 0.027
- Light Navy Blue #2E5A88 ΔE 0.027
- YInMn Blue #415A77 ΔE 0.045
- Denim Blue #3B5B92 ΔE 0.048
- Cobalt #1E488F ΔE 0.050
- Petrol #005F6A ΔE 0.055
Use #1B557F 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.