#243F5B
Closest named color: Dark Grey Blue (#29465B). oklch(36% 0.059 250.6), rgb(36, 63, 91).
Aa
White text reads best on this color (10.84:1).
About this color
#243F5B is a dark, muted blue. In OKLCH its lightness is 36%, its chroma 0.059 and its hue 251°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Grey Blue (#29465B), ΔE 0.025 away. White text reads best on it, at 10.84:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | muted (0.059) |
| Temperature | cool |
| Nearest name | Dark Grey Blue (#29465B) |
| Black text | 1.93:1 |
| White text | 10.84:1 |
Values
| HEX | #243F5B |
| RGB | rgb(36, 63, 91) |
| HSL | hsl(211, 43%, 25%) |
| OKLCH | oklch(36% 0.059 250.6) |
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 #243F5B | 10.84:1 | AAA | Lc -98.9 | Preferred for body text |
| Black text on #243F5B | 1.93:1 | Fails | Lc 8.9 | Not readable |
| #243F5B text on white | 10.84:1 | AAA | Lc 95.0 | Preferred for body text |
| #243F5B text on black | 1.93:1 | Fails | Lc -7.6 | 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
#F3F6F9
oklch(97.2% 0.005 247.9)
-
Step 100
100
#E4EBF2
oklch(93.7% 0.012 248)
-
Step 200
200
#CDDBE9
oklch(88.5% 0.025 248.1)
-
Step 300
300
#ACC3DD
oklch(80.8% 0.045 251.6)
-
Step 400
400
#7FA4CC
oklch(70.6% 0.072 250.8)
-
Step 500
500
#5E8DBF
oklch(63% 0.092 250.9)
-
Step 600
600
#4477AB
oklch(55.7% 0.098 250.4)
-
Step 700
700
#356493
oklch(49.2% 0.092 250.2)
-
Step 800
800
#2D5177
oklch(42.6% 0.076 251.2)
-
Step 900
900 (this color)
#243F5B
oklch(36% 0.059 250.6)
-
Step 950
950
#182838
oklch(27.1% 0.037 249.3)
#243F5B 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) | #33405C | 0.020 |
| Deuteranopia (no green cones) | #2C3B5A | 0.015 |
| Tritanopia (no blue cones) | #004549 | 0.050 |
| Achromatopsia (no color) | #3D3D3D | 0.059 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243F5B
#243F5B
oklch(36% 0.059 250.6)
- #513717
#513717
oklch(36% 0.059 69.5)
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 #243F5B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Grey Blue #29465B ΔE 0.025
- Dark Blue Grey #1F3B4D ΔE 0.027
- Charcoal #264653 ΔE 0.031
- Prussian Blue #1D3557 ΔE 0.034
- Midnight Green #073B4C ΔE 0.040
- Marine Blue #01386A ΔE 0.047
- Onyx #343A40 ΔE 0.048
- Gunmetal #293241 ΔE 0.054
Use #243F5B 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.