#2A3973
Closest named color: Twilight Blue (#0A437A). oklch(36.5% 0.101 269.9), rgb(42, 57, 115).
Aa
White text reads best on this color (10.87:1).
About this color
#2A3973 is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.101 and its hue 270°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.036 away. White text reads best on it, at 10.87:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.101) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.93:1 |
| White text | 10.87:1 |
Values
| HEX | #2A3973 |
| RGB | rgb(42, 57, 115) |
| HSL | hsl(228, 46%, 31%) |
| OKLCH | oklch(36.5% 0.101 269.9) |
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 #2A3973 | 10.87:1 | AAA | Lc -98.9 | Preferred for body text |
| Black text on #2A3973 | 1.93:1 | Fails | Lc 8.9 | Not readable |
| #2A3973 text on white | 10.87:1 | AAA | Lc 95.0 | Preferred for body text |
| #2A3973 text on black | 1.93:1 | Fails | Lc -7.7 | 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
#F3F5FD
oklch(97.1% 0.011 274.9)
-
Step 100
100
#E4EAF9
oklch(93.7% 0.021 268.4)
-
Step 200
200
#CED9F6
oklch(88.6% 0.042 269)
-
Step 300
300
#ADBFF3
oklch(80.9% 0.076 269.8)
-
Step 400
400
#839CEC
oklch(70.7% 0.121 269.9)
-
Step 500
500
#6581E6
oklch(63% 0.155 269.9)
-
Step 600
600
#4E68D5
oklch(55.6% 0.17 270)
-
Step 700
700
#3F56B8
oklch(49% 0.157 269.8)
-
Step 800
800
#344795
oklch(42.7% 0.13 269.8)
-
Step 900
900 (this color)
#2A3973
oklch(36.5% 0.101 269.9)
-
Step 950
950
#1A2446
oklch(27.1% 0.065 269.4)
#2A3973 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) | #1C4075 | 0.023 |
| Deuteranopia (no green cones) | #0F3A72 | 0.027 |
| Tritanopia (no blue cones) | #004650 | 0.087 |
| Achromatopsia (no color) | #3D3D3D | 0.101 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2A3973
#2A3973
oklch(36.5% 0.101 269.9)
- #4E3C00
#4E3C00
oklch(36.5% 0.075 89.6)
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 #2A3973, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.036
- Marine Blue #01386A ΔE 0.040
- Prussian Blue #1D3557 ΔE 0.053
- Cobalt #1E488F ΔE 0.059
- Marine #042E60 ΔE 0.063
- Dark Slate Blue #483D8B ΔE 0.063
- Dark Grey Blue #29465B ΔE 0.064
- Light Navy #155084 ΔE 0.068
Use #2A3973 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.