#2A3979
Closest named color: Twilight Blue (#0A437A). oklch(36.9% 0.11 270.3), rgb(42, 57, 121).
Aa
White text reads best on this color (10.71:1).
About this color
#2A3979 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.110 and its hue 270°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.035 away. White text reads best on it, at 10.71:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.110) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.95:1 |
| White text | 10.71:1 |
Values
| HEX | #2A3979 |
| RGB | rgb(42, 57, 121) |
| HSL | hsl(229, 48%, 32%) |
| OKLCH | oklch(36.9% 0.11 270.3) |
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 #2A3979 | 10.71:1 | AAA | Lc -98.5 | Preferred for body text |
| Black text on #2A3979 | 1.95:1 | Fails | Lc 9.3 | Not readable |
| #2A3979 text on white | 10.71:1 | AAA | Lc 94.6 | Preferred for body text |
| #2A3979 text on black | 1.95:1 | Fails | Lc -8.0 | 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 900.
-
Step 50
50
#F2F5FD
oklch(97% 0.011 269.6)
-
Step 100
100
#E3E9FB
oklch(93.5% 0.025 271.1)
-
Step 200
200
#CDD8F8
oklch(88.4% 0.046 270.4)
-
Step 300
300
#ACBFF7
oklch(81% 0.082 270)
-
Step 400
400
#819BF3
oklch(70.7% 0.132 270.3)
-
Step 500
500
#637FEF
oklch(63% 0.17 270.3)
-
Step 600
600
#4C66DD
oklch(55.6% 0.183 270.1)
-
Step 700
700
#3E54C0
oklch(49.2% 0.171 270.2)
-
Step 800
800
#33459B
oklch(42.7% 0.141 270.4)
-
Step 900
900 (this color)
#2A3979
oklch(36.9% 0.11 270.3)
-
Step 950
950
#1A2348
oklch(27% 0.07 270.8)
#2A3979 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) | #15427B | 0.030 |
| Deuteranopia (no green cones) | #003B78 | 0.033 |
| Tritanopia (no blue cones) | #004853 | 0.094 |
| Achromatopsia (no color) | #3E3E3E | 0.110 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2A3979
#2A3979
oklch(36.9% 0.11 270.3)
- #4F3D00
#4F3D00
oklch(36.9% 0.075 89.9)
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 #2A3979, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.035
- Marine Blue #01386A ΔE 0.045
- Cobalt #1E488F ΔE 0.052
- Dark Slate Blue #483D8B ΔE 0.057
- Prussian Blue #1D3557 ΔE 0.063
- Light Navy #155084 ΔE 0.066
- Marine #042E60 ΔE 0.068
- Blueberry #464196 ΔE 0.068
Use #2A3979 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.