#2591D9
Closest named color: Dark Sky Blue (#448EE4). oklch(63.2% 0.142 243.9), rgb(37, 145, 217).
Aa
Black text reads best on this color (6.13:1).
About this color
#2591D9 is a medium-light, vivid blue. In OKLCH its lightness is 63%, its chroma 0.142 and its hue 244°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Sky Blue (#448EE4), ΔE 0.028 away. Black text reads best on it, at 6.13:1.
| Hue family | Blues |
| Lightness | medium-light (63%) |
| Chroma | vivid (0.142) |
| Temperature | cool |
| Nearest name | Dark Sky Blue (#448EE4) |
| Black text | 6.13:1 |
| White text | 3.42:1 |
Values
| HEX | #2591D9 |
| RGB | rgb(37, 145, 217) |
| HSL | hsl(204, 71%, 50%) |
| OKLCH | oklch(63.2% 0.142 243.9) |
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 #2591D9 | 3.42:1 | AA large text | Lc -66.8 | Content text, not long reading |
| Black text on #2591D9 | 6.13:1 | AA | Lc 42.8 | Non-text elements, placeholder text |
| #2591D9 text on white | 3.42:1 | AA large text | Lc 61.3 | Content text, not long reading |
| #2591D9 text on black | 6.13:1 | AA | Lc -40.4 | 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 500.
-
Step 50
50
#F0F6FB
oklch(97% 0.009 242.8)
-
Step 100
100
#DFECF7
oklch(93.7% 0.02 243.4)
-
Step 200
200
#C4DDF1
oklch(88.5% 0.038 242.2)
-
Step 300
300
#9AC6EB
oklch(80.8% 0.07 244.2)
-
Step 400
400
#5FA8E1
oklch(70.7% 0.111 243.9)
-
Step 500
500 (this color)
#2591D9
oklch(63.2% 0.142 243.9)
-
Step 600
600
#0079BD
oklch(55.5% 0.138 244.2)
-
Step 700
700
#0066A0
oklch(49.2% 0.121 244)
-
Step 800
800
#005384
oklch(42.6% 0.106 244.3)
-
Step 900
900
#00456F
oklch(37.6% 0.093 244.3)
-
Step 950
950
#062941
oklch(27% 0.059 243.6)
#2591D9 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) | #6F93DC | 0.062 |
| Deuteranopia (no green cones) | #5683D8 | 0.047 |
| Tritanopia (no blue cones) | #00A3AB | 0.099 |
| Achromatopsia (no color) | #8B8B8B | 0.143 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2591D9
#2591D9
oklch(63.2% 0.142 243.9)
- #C47403
#C47403
oklch(63.3% 0.142 64.1)
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 #2591D9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Sky Blue #448EE4 ΔE 0.028
- Water Blue #0E87CC ΔE 0.034
- Chefchaouen Blue #4895EF ΔE 0.042
- Cool Blue #4984B8 ΔE 0.056
- Dodger Blue #1E90FF ΔE 0.058
- Cornflower Blue #6495ED ΔE 0.060
- Soft Blue #6488EA ΔE 0.061
- Blue NCS #118AB2 ΔE 0.061
Use #2591D9 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.