#1B4B9B
Closest named color: Cobalt (#1E488F). oklch(42.9% 0.141 260.2), rgb(27, 75, 155).
Aa
White text reads best on this color (8.31:1).
About this color
#1B4B9B is a dark, vivid blue. In OKLCH its lightness is 43%, its chroma 0.141 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.020 away. White text reads best on it, at 8.31:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | vivid (0.141) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.52:1 |
| White text | 8.31:1 |
Values
| HEX | #1B4B9B |
| RGB | rgb(27, 75, 155) |
| HSL | hsl(218, 70%, 36%) |
| OKLCH | oklch(42.9% 0.141 260.2) |
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 #1B4B9B | 8.31:1 | AAA | Lc -92.8 | Preferred for body text |
| Black text on #1B4B9B | 2.52:1 | Fails | Lc 15.8 | Dividers and decoration only |
| #1B4B9B text on white | 8.31:1 | AAA | Lc 88.2 | Fine for body text |
| #1B4B9B text on black | 2.52:1 | Fails | Lc -14.0 | 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
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E1EBFA
oklch(93.7% 0.023 258.4)
-
Step 200
200
#C8DAF8
oklch(88.4% 0.046 260.7)
-
Step 300
300
#A2C2F6
oklch(80.9% 0.082 260)
-
Step 400
400
#6FA0F2
oklch(70.6% 0.132 260.2)
-
Step 500
500
#4986ED
oklch(63.1% 0.168 260.2)
-
Step 600
600
#2A6DDC
oklch(55.6% 0.183 260.1)
-
Step 700
700
#1D5ABF
oklch(49% 0.171 260.2)
-
Step 800
800 (this color)
#1B4B9B
oklch(42.9% 0.141 260.2)
-
Step 900
900
#1C3F7B
oklch(37.7% 0.11 260.4)
-
Step 950
950
#112548
oklch(26.9% 0.07 260.7)
#1B4B9B 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) | #17549E | 0.025 |
| Deuteranopia (no green cones) | #004999 | 0.015 |
| Tritanopia (no blue cones) | #005E6B | 0.108 |
| Achromatopsia (no color) | #4E4E4E | 0.141 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B4B9B
#1B4B9B
oklch(42.9% 0.141 260.2)
- #694900
#694900
oklch(43% 0.089 79.8)
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 #1B4B9B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.020
- Dusk Blue #26538D ΔE 0.036
- Light Navy #155084 ΔE 0.043
- Blueberry #464196 ΔE 0.052
- Sapphire #2138AB ΔE 0.053
- Deep Sea Blue #015482 ΔE 0.053
- Twilight Blue #0A437A ΔE 0.060
- Light Navy Blue #2E5A88 ΔE 0.061
Use #1B4B9B 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.