#257DD4
Closest named color: Water Blue (#0E87CC). oklch(58.4% 0.156 252.3), rgb(37, 125, 212).
Aa
Black text reads best on this color (4.96:1).
About this color
#257DD4 is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.156 and its hue 252°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.032 away. Black text reads best on it, at 4.96:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.156) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 4.96:1 |
| White text | 4.23:1 |
Values
| HEX | #257DD4 |
| RGB | rgb(37, 125, 212) |
| HSL | hsl(210, 70%, 49%) |
| OKLCH | oklch(58.4% 0.156 252.3) |
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 #257DD4 | 4.23:1 | AA large text | Lc -74.2 | Content text, not long reading |
| Black text on #257DD4 | 4.96:1 | AA | Lc 35.4 | Non-text elements, placeholder text |
| #257DD4 text on white | 4.23:1 | AA large text | Lc 68.7 | Content text, not long reading |
| #257DD4 text on black | 4.96:1 | AA | Lc -32.9 | 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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF7
oklch(93.6% 0.019 252.9)
-
Step 200
200
#C7DBF3
oklch(88.4% 0.04 253)
-
Step 300
300
#A0C4ED
oklch(80.8% 0.07 252)
-
Step 400
400
#6BA4E5
oklch(70.6% 0.113 252.6)
-
Step 500
500
#408CDD
oklch(63.1% 0.144 252.3)
-
Step 600
600 (this color)
#257DD4
oklch(58.4% 0.156 252.3)
-
Step 700
700
#0761AF
oklch(49% 0.145 252.3)
-
Step 800
800
#0E508E
oklch(42.8% 0.12 252.2)
-
Step 900
900
#164371
oklch(37.8% 0.093 252.1)
-
Step 950
950
#0E2742
oklch(26.9% 0.059 252.4)
#257DD4 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) | #5283D7 | 0.041 |
| Deuteranopia (no green cones) | #3374D2 | 0.024 |
| Tritanopia (no blue cones) | #00929E | 0.116 |
| Achromatopsia (no color) | #7B7B7B | 0.156 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #257DD4
#257DD4
oklch(58.4% 0.156 252.3)
- #A86D00
#A86D00
oklch(58.4% 0.125 72.1)
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 #257DD4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.032
- Windows Blue #3778BF ΔE 0.033
- Dark Sky Blue #448EE4 ΔE 0.057
- Cool Blue #4984B8 ΔE 0.057
- Nice Blue #107AB0 ΔE 0.058
- Royal Blue #4169E1 ΔE 0.058
- Steel Blue #4682B4 ΔE 0.058
- Cerulean Blue #056EEE ΔE 0.061
Use #257DD4 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.