#257BB9
Closest named color: Nice Blue (#107AB0). oklch(56.3% 0.124 245), rgb(37, 123, 185).
Aa
Black text reads best on this color (4.61:1).
About this color
#257BB9 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 56%, its chroma 0.124 and its hue 245°. Its hue sits on the cool side of the wheel. The nearest named color is Nice Blue (#107AB0), ΔE 0.017 away. Black text reads best on it, at 4.61:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.124) |
| Temperature | cool |
| Nearest name | Nice Blue (#107AB0) |
| Black text | 4.61:1 |
| White text | 4.55:1 |
Values
| HEX | #257BB9 |
| RGB | rgb(37, 123, 185) |
| HSL | hsl(205, 67%, 44%) |
| OKLCH | oklch(56.3% 0.124 245) |
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 #257BB9 | 4.55:1 | AA | Lc -76.7 | Fine for body text |
| Black text on #257BB9 | 4.61:1 | AA | Lc 32.9 | Non-text elements, placeholder text |
| #257BB9 text on white | 4.55:1 | AA | Lc 71.2 | Content text, not long reading |
| #257BB9 text on black | 4.61:1 | AA | Lc -30.5 | Non-text elements, placeholder text |
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 600.
-
Step 50
50
#F1F6FA
oklch(97.1% 0.008 241.7)
-
Step 100
100
#E1EBF4
oklch(93.5% 0.016 245.1)
-
Step 200
200
#C9DCED
oklch(88.6% 0.031 245.1)
-
Step 300
300
#A3C5E3
oklch(80.9% 0.056 245.2)
-
Step 400
400
#70A7D5
oklch(70.8% 0.089 244.8)
-
Step 500
500
#4690CA
oklch(63.2% 0.115 244.8)
-
Step 600
600 (this color)
#257BB9
oklch(56.3% 0.124 245)
-
Step 700
700
#13659D
oklch(49% 0.116 245.2)
-
Step 800
800
#145380
oklch(42.7% 0.096 245.1)
-
Step 900
900
#194566
oklch(37.7% 0.074 244.5)
-
Step 950
950
#10293C
oklch(27.1% 0.047 243.8)
#257BB9 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) | #5E7DBC | 0.052 |
| Deuteranopia (no green cones) | #4970B8 | 0.038 |
| Tritanopia (no blue cones) | #008A91 | 0.088 |
| Achromatopsia (no color) | #767676 | 0.125 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #257BB9
#257BB9
oklch(56.3% 0.124 245)
- #A66306
#A66306
oklch(56.2% 0.124 64.9)
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 #257BB9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Nice Blue #107AB0 ΔE 0.017
- Windows Blue #3778BF ΔE 0.018
- Flat Blue #3C73A8 ΔE 0.032
- Steel Blue #4682B4 ΔE 0.035
- Water Blue #0E87CC ΔE 0.039
- Cool Blue #4984B8 ΔE 0.041
- Muted Blue #3B719F ΔE 0.044
- French Blue #436BAD ΔE 0.046
Use #257BB9 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.