#2A378C
Closest named color: Cobalt (#1E488F). oklch(38.1% 0.141 271.4), rgb(42, 55, 140).
Aa
White text reads best on this color (10.37:1).
About this color
#2A378C is a dark, vivid blue. In OKLCH its lightness is 38%, its chroma 0.141 and its hue 271°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.044 away. White text reads best on it, at 10.37:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | vivid (0.141) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.02:1 |
| White text | 10.37:1 |
Values
| HEX | #2A378C |
| RGB | rgb(42, 55, 140) |
| HSL | hsl(232, 54%, 36%) |
| OKLCH | oklch(38.1% 0.141 271.4) |
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 #2A378C | 10.37:1 | AAA | Lc -97.7 | Preferred for body text |
| Black text on #2A378C | 2.02:1 | Fails | Lc 10.3 | Not readable |
| #2A378C text on white | 10.37:1 | AAA | Lc 93.6 | Preferred for body text |
| #2A378C text on black | 2.02:1 | Fails | Lc -8.9 | 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 900.
-
Step 50
50
#F2F5FF
oklch(97.1% 0.014 272.7)
-
Step 100
100
#E2E9FF
oklch(93.5% 0.031 271.7)
-
Step 200
200
#CBD8FF
oklch(88.5% 0.056 270.7)
-
Step 300
300
#AABDFF
oklch(80.8% 0.096 271.7)
-
Step 400
400
#7F99FF
oklch(70.8% 0.152 271.3)
-
Step 500
500
#617AFF
oklch(63% 0.198 271.6)
-
Step 600
600
#485AF9
oklch(55.5% 0.235 271.3)
-
Step 700
700
#3B48D9
oklch(49% 0.218 271.4)
-
Step 800
800
#303DB0
oklch(42.8% 0.181 271.3)
-
Step 900
900 (this color)
#2A378C
oklch(38.1% 0.141 271.4)
-
Step 950
950
#182151
oklch(27.1% 0.088 271.3)
#2A378C 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) | #00458F | 0.042 |
| Deuteranopia (no green cones) | #003C8A | 0.032 |
| Tritanopia (no blue cones) | #004C5C | 0.114 |
| Achromatopsia (no color) | #404040 | 0.141 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2A378C
#2A378C
oklch(38.1% 0.141 271.4)
- #524000
#524000
oklch(38% 0.078 90.6)
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 #2A378C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.044
- Dark Slate Blue #483D8B ΔE 0.050
- Twilight Blue #0A437A ΔE 0.052
- Sapphire #2138AB ΔE 0.052
- Blueberry #464196 ΔE 0.054
- Marine Blue #01386A ΔE 0.070
- Light Navy #155084 ΔE 0.072
- Dusk Blue #26538D ΔE 0.077
Use #2A378C 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.