#243F51
Closest named color: Dark Blue Grey (#1F3B4D). oklch(35.4% 0.046 239.1), rgb(36, 63, 81).
Aa
White text reads best on this color (11.02:1).
About this color
#243F51 is a dark, muted blue. In OKLCH its lightness is 35%, its chroma 0.046 and its hue 239°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Blue Grey (#1F3B4D), ΔE 0.016 away. White text reads best on it, at 11.02:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | muted (0.046) |
| Temperature | cool |
| Nearest name | Dark Blue Grey (#1F3B4D) |
| Black text | 1.90:1 |
| White text | 11.02:1 |
Values
| HEX | #243F51 |
| RGB | rgb(36, 63, 81) |
| HSL | hsl(204, 38%, 23%) |
| OKLCH | oklch(35.4% 0.046 239.1) |
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 #243F51 | 11.02:1 | AAA | Lc -99.3 | Preferred for body text |
| Black text on #243F51 | 1.90:1 | Fails | Lc 8.5 | Not readable |
| #243F51 text on white | 11.02:1 | AAA | Lc 95.4 | Preferred for body text |
| #243F51 text on black | 1.90:1 | 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
#F3F6F8
oklch(97.1% 0.004 236.5)
-
Step 100
100
#E4EBF0
oklch(93.6% 0.01 238.5)
-
Step 200
200
#CEDBE5
oklch(88.5% 0.02 240.8)
-
Step 300
300
#ADC4D5
oklch(80.8% 0.035 240)
-
Step 400
400
#81A6BF
oklch(70.7% 0.055 238.1)
-
Step 500
500
#6190AF
oklch(63.2% 0.069 238.2)
-
Step 600
600
#47799B
oklch(55.5% 0.076 239.8)
-
Step 700
700
#386685
oklch(49.1% 0.071 239.9)
-
Step 800
800
#2F536C
oklch(42.6% 0.059 240.4)
-
Step 900
900 (this color)
#243F51
oklch(35.4% 0.046 239.1)
-
Step 950
950
#192833
oklch(26.9% 0.029 241)
#243F51 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) | #373F52 | 0.026 |
| Deuteranopia (no green cones) | #313A51 | 0.022 |
| Tritanopia (no blue cones) | #0C4445 | 0.037 |
| Achromatopsia (no color) | #3C3C3C | 0.046 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243F51
#243F51
oklch(35.4% 0.046 239.1)
- #4E3623
#4E3623
oklch(35.6% 0.046 59)
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 #243F51, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Blue Grey #1F3B4D ΔE 0.016
- Charcoal #264653 ΔE 0.023
- Dark Grey Blue #29465B ΔE 0.027
- Midnight Green #073B4C ΔE 0.031
- Onyx #343A40 ΔE 0.034
- Prussian Blue #1D3557 ΔE 0.039
- Charcoal Grey #3C4142 ΔE 0.043
- Gunmetal #293241 ΔE 0.044
Use #243F51 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.