#255DB4
Closest named color: Mid Blue (#276AB3). oklch(49.1% 0.15 259.2), rgb(37, 93, 180).
Aa
White text reads best on this color (6.35:1).
About this color
#255DB4 is a medium-dark, vivid blue. In OKLCH its lightness is 49%, its chroma 0.150 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Mid Blue (#276AB3), ΔE 0.037 away. White text reads best on it, at 6.35:1.
| Hue family | Blues |
| Lightness | medium-dark (49%) |
| Chroma | vivid (0.150) |
| Temperature | cool |
| Nearest name | Mid Blue (#276AB3) |
| Black text | 3.30:1 |
| White text | 6.35:1 |
Values
| HEX | #255DB4 |
| RGB | rgb(37, 93, 180) |
| HSL | hsl(217, 66%, 43%) |
| OKLCH | oklch(49.1% 0.15 259.2) |
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 #255DB4 | 6.35:1 | AA | Lc -86.3 | Fine for body text |
| Black text on #255DB4 | 3.30:1 | AA large text | Lc 22.9 | Dividers and decoration only |
| #255DB4 text on white | 6.35:1 | AA | Lc 81.2 | Fine for body text |
| #255DB4 text on black | 3.30:1 | AA large text | Lc -20.7 | Dividers and decoration only |
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 700.
-
Step 50
50
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E2EBF8
oklch(93.7% 0.02 257.5)
-
Step 200
200
#CADAF4
oklch(88.4% 0.04 260.1)
-
Step 300
300
#A5C2F0
oklch(80.9% 0.073 259.5)
-
Step 400
400
#74A1E9
oklch(70.6% 0.117 259.5)
-
Step 500
500
#4F88E2
oklch(63.1% 0.149 259.2)
-
Step 600
600
#3270D0
oklch(55.6% 0.162 259.1)
-
Step 700
700 (this color)
#255DB4
oklch(49.1% 0.15 259.2)
-
Step 800
800
#204C92
oklch(42.6% 0.125 259.4)
-
Step 900
900
#1F4074
oklch(37.6% 0.097 259.2)
-
Step 950
950
#132644
oklch(27% 0.061 259.2)
#255DB4 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) | #2B66B7 | 0.026 |
| Deuteranopia (no green cones) | #0059B2 | 0.022 |
| Tritanopia (no blue cones) | #007280 | 0.116 |
| Achromatopsia (no color) | #5F5F5F | 0.150 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #255DB4
#255DB4
oklch(49.1% 0.15 259.2)
- #7F5900
#7F5900
oklch(49.2% 0.102 79.8)
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 #255DB4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Mid Blue #276AB3 ΔE 0.037
- French Blue #436BAD ΔE 0.054
- Denim Blue #3B5B92 ΔE 0.056
- Dusky Blue #475F94 ΔE 0.061
- Peacock Blue #016795 ΔE 0.064
- Dusk Blue #26538D ΔE 0.066
- Light Navy Blue #2E5A88 ΔE 0.070
- Denim #3B638C ΔE 0.072
Use #255DB4 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.