#1B4FA1
Closest named color: Cobalt (#1E488F). oklch(44.3% 0.144 259.5), rgb(27, 79, 161).
Aa
White text reads best on this color (7.83:1).
About this color
#1B4FA1 is a dark, vivid blue. In OKLCH its lightness is 44%, its chroma 0.144 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.033 away. White text reads best on it, at 7.83:1.
| Hue family | Blues |
| Lightness | dark (44%) |
| Chroma | vivid (0.144) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.67:1 |
| White text | 7.83:1 |
Values
| HEX | #1B4FA1 |
| RGB | rgb(27, 79, 161) |
| HSL | hsl(217, 71%, 37%) |
| OKLCH | oklch(44.3% 0.144 259.5) |
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 #1B4FA1 | 7.83:1 | AAA | Lc -91.5 | Preferred for body text |
| Black text on #1B4FA1 | 2.67:1 | Fails | Lc 17.3 | Dividers and decoration only |
| #1B4FA1 text on white | 7.83:1 | AAA | Lc 86.7 | Fine for body text |
| #1B4FA1 text on black | 2.67:1 | Fails | Lc -15.4 | 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
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E0EBFB
oklch(93.7% 0.025 257.6)
-
Step 200
200
#C7DAF9
oklch(88.4% 0.048 260.2)
-
Step 300
300
#A1C2F7
oklch(80.9% 0.084 259.8)
-
Step 400
400
#6DA1F4
oklch(70.8% 0.134 259.4)
-
Step 500
500
#4586F0
oklch(63.1% 0.173 259.7)
-
Step 600
600
#256DDE
oklch(55.6% 0.187 259.6)
-
Step 700
700
#175AC1
oklch(49.1% 0.174 259.6)
-
Step 800
800 (this color)
#1B4FA1
oklch(44.3% 0.144 259.5)
-
Step 900
900
#193F7C
oklch(37.7% 0.112 259.6)
-
Step 950
950
#102549
oklch(26.9% 0.072 260.4)
#1B4FA1 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) | #1B58A4 | 0.025 |
| Deuteranopia (no green cones) | #004C9F | 0.016 |
| Tritanopia (no blue cones) | #006370 | 0.111 |
| Achromatopsia (no color) | #525252 | 0.144 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B4FA1
#1B4FA1
oklch(44.3% 0.144 259.5)
- #6E4C00
#6E4C00
oklch(44.2% 0.092 79.1)
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 #1B4FA1, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.033
- Dusk Blue #26538D ΔE 0.037
- Light Navy #155084 ΔE 0.049
- Denim Blue #3B5B92 ΔE 0.056
- Blueberry #464196 ΔE 0.056
- Deep Sea Blue #015482 ΔE 0.057
- Sapphire #2138AB ΔE 0.059
- Light Navy Blue #2E5A88 ΔE 0.059
Use #1B4FA1 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.