#1B488B
Closest named color: Cobalt (#1E488F). oklch(41% 0.122 258.6), rgb(27, 72, 139).
Aa
White text reads best on this color (8.95:1).
About this color
#1B488B is a dark, moderately saturated blue. In OKLCH its lightness is 41%, its chroma 0.122 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.007 away. White text reads best on it, at 8.95:1.
| Hue family | Blues |
| Lightness | dark (41%) |
| Chroma | moderately saturated (0.122) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.34:1 |
| White text | 8.95:1 |
Values
| HEX | #1B488B |
| RGB | rgb(27, 72, 139) |
| HSL | hsl(216, 67%, 33%) |
| OKLCH | oklch(41% 0.122 258.6) |
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 #1B488B | 8.95:1 | AAA | Lc -94.6 | Preferred for body text |
| Black text on #1B488B | 2.34:1 | Fails | Lc 13.9 | Not readable |
| #1B488B text on white | 8.95:1 | AAA | Lc 90.1 | Preferred for body text |
| #1B488B text on black | 2.34:1 | Fails | Lc -12.2 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E2EBF8
oklch(93.7% 0.02 257.5)
-
Step 200
200
#CADAF4
oklch(88.4% 0.04 260.1)
-
Step 300
300
#A5C2EF
oklch(80.8% 0.071 259.1)
-
Step 400
400
#74A2E7
oklch(70.8% 0.113 258.3)
-
Step 500
500
#4F89E0
oklch(63.2% 0.145 258.3)
-
Step 600
600
#3270CE
oklch(55.5% 0.159 258.7)
-
Step 700
700
#255EB2
oklch(49.2% 0.146 258.5)
-
Step 800
800 (this color)
#1B488B
oklch(41% 0.122 258.6)
-
Step 900
900
#1F4173
oklch(37.8% 0.095 258.1)
-
Step 950
950
#132643
oklch(26.9% 0.06 258.6)
#1B488B 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) | #234F8E | 0.023 |
| Deuteranopia (no green cones) | #03458A | 0.017 |
| Tritanopia (no blue cones) | #005862 | 0.095 |
| Achromatopsia (no color) | #494949 | 0.122 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B488B
#1B488B
oklch(41% 0.122 258.6)
- #634400
#634400
oklch(41.1% 0.085 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 #1B488B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.007
- Light Navy #155084 ΔE 0.028
- Twilight Blue #0A437A ΔE 0.034
- Dusk Blue #26538D ΔE 0.035
- Deep Sea Blue #015482 ΔE 0.041
- Blueberry #464196 ΔE 0.056
- Dark Slate Blue #483D8B ΔE 0.059
- Light Navy Blue #2E5A88 ΔE 0.060
Use #1B488B 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.