#1B537F
Closest named color: Deep Sea Blue (#015482). oklch(42.9% 0.093 246.3), rgb(27, 83, 127).
Aa
White text reads best on this color (8.10:1).
About this color
#1B537F is a dark, moderately saturated blue. In OKLCH its lightness is 43%, its chroma 0.093 and its hue 246°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sea Blue (#015482), ΔE 0.011 away. White text reads best on it, at 8.10:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | moderately saturated (0.093) |
| Temperature | cool |
| Nearest name | Deep Sea Blue (#015482) |
| Black text | 2.59:1 |
| White text | 8.10:1 |
Values
| HEX | #1B537F |
| RGB | rgb(27, 83, 127) |
| HSL | hsl(206, 65%, 30%) |
| OKLCH | oklch(42.9% 0.093 246.3) |
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 #1B537F | 8.10:1 | AAA | Lc -92.4 | Preferred for body text |
| Black text on #1B537F | 2.59:1 | Fails | Lc 16.3 | Dividers and decoration only |
| #1B537F text on white | 8.10:1 | AAA | Lc 87.7 | Fine for body text |
| #1B537F text on black | 2.59:1 | Fails | Lc -14.4 | 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
#CADCEC
oklch(88.6% 0.029 244.9)
-
Step 300
300
#A5C5E2
oklch(81% 0.054 245.9)
-
Step 400
400
#73A6D4
oklch(70.7% 0.087 246.6)
-
Step 500
500
#4B8FC9
oklch(63.1% 0.112 246.5)
-
Step 600
600
#2B78B5
oklch(55.5% 0.12 246.5)
-
Step 700
700
#1C659C
oklch(49.1% 0.112 246.2)
-
Step 800
800 (this color)
#1B537F
oklch(42.9% 0.093 246.3)
-
Step 900
900
#1D4566
oklch(37.8% 0.072 246.2)
-
Step 950
950
#12283B
oklch(26.9% 0.045 246.6)
#1B537F 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) | #3F5581 | 0.038 |
| Deuteranopia (no green cones) | #304B7E | 0.028 |
| Tritanopia (no blue cones) | #005E63 | 0.067 |
| Achromatopsia (no color) | #505050 | 0.093 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B537F
#1B537F
oklch(42.9% 0.093 246.3)
- #714304
#714304
oklch(42.8% 0.093 66)
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 #1B537F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sea Blue #015482 ΔE 0.011
- Light Navy #155084 ΔE 0.014
- Dusk Blue #26538D ΔE 0.026
- Light Navy Blue #2E5A88 ΔE 0.031
- Cobalt #1E488F ΔE 0.045
- YInMn Blue #415A77 ΔE 0.049
- Denim Blue #3B5B92 ΔE 0.051
- Twilight Blue #0A437A ΔE 0.051
Use #1B537F 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.