#2566BF
Closest named color: Mid Blue (#276AB3). oklch(51.9% 0.154 257.5), rgb(37, 102, 191).
Aa
White text reads best on this color (5.62:1).
About this color
#2566BF is a medium-dark, vivid blue. In OKLCH its lightness is 52%, its chroma 0.154 and its hue 258°. Its hue sits on the cool side of the wheel. The nearest named color is Mid Blue (#276AB3), ΔE 0.023 away. White text reads best on it, at 5.62:1.
| Hue family | Blues |
| Lightness | medium-dark (52%) |
| Chroma | vivid (0.154) |
| Temperature | cool |
| Nearest name | Mid Blue (#276AB3) |
| Black text | 3.73:1 |
| White text | 5.62:1 |
Values
| HEX | #2566BF |
| RGB | rgb(37, 102, 191) |
| HSL | hsl(215, 68%, 45%) |
| OKLCH | oklch(51.9% 0.154 257.5) |
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 #2566BF | 5.62:1 | AA | Lc -83.0 | Fine for body text |
| Black text on #2566BF | 3.73:1 | AA large text | Lc 26.4 | Dividers and decoration only |
| #2566BF text on white | 5.62:1 | AA | Lc 77.7 | Fine for body text |
| #2566BF text on black | 3.73:1 | AA large text | Lc -24.1 | 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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF9
oklch(93.7% 0.022 256.7)
-
Step 200
200
#C8DBF5
oklch(88.5% 0.041 256.2)
-
Step 300
300
#A3C3F1
oklch(81% 0.074 257.4)
-
Step 400
400
#70A2EA
oklch(70.7% 0.119 257.5)
-
Step 500
500
#4989E4
oklch(63.2% 0.153 257.5)
-
Step 600
600
#2971D2
oklch(55.7% 0.166 257.3)
-
Step 700
700 (this color)
#2566BF
oklch(51.9% 0.154 257.5)
-
Step 800
800
#1A4D93
oklch(42.7% 0.127 257.5)
-
Step 900
900
#1B4175
oklch(37.7% 0.099 257.1)
-
Step 950
950
#112645
oklch(27% 0.064 258.1)
#2566BF 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) | #356FC2 | 0.029 |
| Deuteranopia (no green cones) | #0861BD | 0.021 |
| Tritanopia (no blue cones) | #007B89 | 0.118 |
| Achromatopsia (no color) | #676767 | 0.154 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2566BF
#2566BF
oklch(51.9% 0.154 257.5)
- #8B5F00
#8B5F00
oklch(51.9% 0.109 77.2)
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 #2566BF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Mid Blue #276AB3 ΔE 0.023
- French Blue #436BAD ΔE 0.043
- Windows Blue #3778BF ΔE 0.054
- Royal Blue #4169E1 ΔE 0.060
- Flat Blue #3C73A8 ΔE 0.060
- Nice Blue #107AB0 ΔE 0.065
- Warm Blue #4B57DB ΔE 0.067
- Muted Blue #3B719F ΔE 0.067
Use #2566BF 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.