#243A58
Closest named color: Prussian Blue (#1D3557). oklch(34.5% 0.06 256.4), rgb(36, 58, 88).
Aa
White text reads best on this color (11.53:1).
About this color
#243A58 is a dark, muted blue. In OKLCH its lightness is 35%, its chroma 0.060 and its hue 256°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.019 away. White text reads best on it, at 11.53:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | muted (0.060) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.82:1 |
| White text | 11.53:1 |
Values
| HEX | #243A58 |
| RGB | rgb(36, 58, 88) |
| HSL | hsl(215, 42%, 24%) |
| OKLCH | oklch(34.5% 0.06 256.4) |
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 #243A58 | 11.53:1 | AAA | Lc -100.1 | Preferred for body text |
| Black text on #243A58 | 1.82:1 | Fails | Lc 7.4 | Not readable |
| #243A58 text on white | 11.53:1 | AAA | Lc 96.4 | Preferred for body text |
| #243A58 text on black | 1.82:1 | 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
#E4EAF3
oklch(93.5% 0.014 258.3)
-
Step 200
200
#CFDAEA
oklch(88.5% 0.025 257.6)
-
Step 300
300
#AEC2DE
oklch(80.8% 0.045 256.8)
-
Step 400
400
#84A3CD
oklch(70.8% 0.071 256.1)
-
Step 500
500
#648BC1
oklch(63% 0.093 256.7)
-
Step 600
600
#4B75AD
oklch(55.7% 0.1 256)
-
Step 700
700
#3C6295
oklch(49.2% 0.093 256.2)
-
Step 800
800
#325079
oklch(42.8% 0.077 256.5)
-
Step 900
900 (this color)
#243A58
oklch(34.5% 0.06 256.4)
-
Step 950
950
#1A2739
oklch(27% 0.038 256.7)
#243A58 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) | #2E3C59 | 0.016 |
| Deuteranopia (no green cones) | #273757 | 0.010 |
| Tritanopia (no blue cones) | #054145 | 0.053 |
| Achromatopsia (no color) | #393939 | 0.060 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243A58
#243A58
oklch(34.5% 0.06 256.4)
- #4B3510
#4B3510
oklch(34.6% 0.06 77.1)
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 #243A58, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.019
- Dark Blue Grey #1F3B4D ΔE 0.022
- Midnight Green #073B4C ΔE 0.035
- Dark Grey Blue #29465B ΔE 0.040
- Marine Blue #01386A ΔE 0.042
- Gunmetal #293241 ΔE 0.043
- Charcoal #264653 ΔE 0.043
- Onyx #343A40 ΔE 0.047
Use #243A58 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.