#1B4688
Closest named color: Cobalt (#1E488F). oklch(40.3% 0.12 259), rgb(27, 70, 136).
Aa
White text reads best on this color (9.21:1).
About this color
#1B4688 is a dark, moderately saturated blue. In OKLCH its lightness is 40%, its chroma 0.120 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.013 away. White text reads best on it, at 9.21:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | moderately saturated (0.120) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.27:1 |
| White text | 9.21:1 |
Values
| HEX | #1B4688 |
| RGB | rgb(27, 70, 136) |
| HSL | hsl(216, 67%, 32%) |
| OKLCH | oklch(40.3% 0.12 259) |
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 #1B4688 | 9.21:1 | AAA | Lc -95.2 | Preferred for body text |
| Black text on #1B4688 | 2.27:1 | Fails | Lc 13.1 | Not readable |
| #1B4688 text on white | 9.21:1 | AAA | Lc 90.9 | Preferred for body text |
| #1B4688 text on black | 2.27:1 | Fails | Lc -11.5 | 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
#A6C2EF
oklch(80.9% 0.071 259.8)
-
Step 400
400
#75A2E6
oklch(70.8% 0.112 258.4)
-
Step 500
500
#5189DF
oklch(63.2% 0.143 258.7)
-
Step 600
600
#3570CD
oklch(55.5% 0.157 259.3)
-
Step 700
700
#275EB1
oklch(49.2% 0.144 258.7)
-
Step 800
800 (this color)
#1B4688
oklch(40.3% 0.12 259)
-
Step 900
900
#214173
oklch(37.8% 0.094 259)
-
Step 950
950
#142643
oklch(27% 0.059 259.5)
#1B4688 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) | #224D8A | 0.022 |
| Deuteranopia (no green cones) | #024387 | 0.018 |
| Tritanopia (no blue cones) | #005660 | 0.094 |
| Achromatopsia (no color) | #484848 | 0.120 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B4688
#1B4688
oklch(40.3% 0.12 259)
- #604200
#604200
oklch(40.2% 0.084 79.3)
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 #1B4688, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.013
- Twilight Blue #0A437A ΔE 0.028
- Light Navy #155084 ΔE 0.031
- Dusk Blue #26538D ΔE 0.041
- Deep Sea Blue #015482 ΔE 0.044
- Blueberry #464196 ΔE 0.058
- Dark Slate Blue #483D8B ΔE 0.059
- Light Navy Blue #2E5A88 ΔE 0.065
Use #1B4688 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.