#243A5E
Closest named color: Prussian Blue (#1D3557). oklch(34.9% 0.069 259.8), rgb(36, 58, 94).
Aa
White text reads best on this color (11.40:1).
About this color
#243A5E is a dark, muted blue. In OKLCH its lightness is 35%, its chroma 0.069 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.022 away. White text reads best on it, at 11.40:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | muted (0.069) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.84:1 |
| White text | 11.40:1 |
Values
| HEX | #243A5E |
| RGB | rgb(36, 58, 94) |
| HSL | hsl(217, 45%, 25%) |
| OKLCH | oklch(34.9% 0.069 259.8) |
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 #243A5E | 11.40:1 | AAA | Lc -99.9 | Preferred for body text |
| Black text on #243A5E | 1.84:1 | Fails | Lc 7.7 | Not readable |
| #243A5E text on white | 11.40:1 | AAA | Lc 96.2 | Preferred for body text |
| #243A5E text on black | 1.84:1 | Fails | Lc 0.0 | 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
#F3F6FA
oklch(97.2% 0.006 255.5)
-
Step 100
100
#E4EAF4
oklch(93.5% 0.015 260.7)
-
Step 200
200
#CEDAED
oklch(88.5% 0.029 259.6)
-
Step 300
300
#ADC2E3
oklch(80.9% 0.052 259.4)
-
Step 400
400
#82A2D5
oklch(70.8% 0.083 259.6)
-
Step 500
500
#638AC9
oklch(63.1% 0.105 259.7)
-
Step 600
600
#4973B6
oklch(55.6% 0.115 259.4)
-
Step 700
700
#3B609D
oklch(49.1% 0.107 259.9)
-
Step 800
800
#314F7F
oklch(42.8% 0.088 259.4)
-
Step 900
900 (this color)
#243A5E
oklch(34.9% 0.069 259.8)
-
Step 950
950
#19273C
oklch(27.1% 0.044 258.3)
#243A5E 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) | #2B3D5F | 0.014 |
| Deuteranopia (no green cones) | #24375D | 0.009 |
| Tritanopia (no blue cones) | #004247 | 0.061 |
| Achromatopsia (no color) | #3A3A3A | 0.069 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243A5E
#243A5E
oklch(34.9% 0.069 259.8)
- #4D3504
#4D3504
oklch(34.8% 0.069 79.2)
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 #243A5E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.022
- Dark Blue Grey #1F3B4D ΔE 0.033
- Marine Blue #01386A ΔE 0.035
- Dark Grey Blue #29465B ΔE 0.042
- Midnight Green #073B4C ΔE 0.043
- Charcoal #264653 ΔE 0.049
- Gunmetal #293241 ΔE 0.052
- Twilight Blue #0A437A ΔE 0.052
Use #243A5E 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.