#2591DD
Closest named color: Dark Sky Blue (#448EE4). oklch(63.5% 0.147 245.3), rgb(37, 145, 221).
Aa
Black text reads best on this color (6.17:1).
About this color
#2591DD is a medium-light, vivid blue. In OKLCH its lightness is 63%, its chroma 0.147 and its hue 245°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Sky Blue (#448EE4), ΔE 0.023 away. Black text reads best on it, at 6.17:1.
| Hue family | Blues |
| Lightness | medium-light (63%) |
| Chroma | vivid (0.147) |
| Temperature | cool |
| Nearest name | Dark Sky Blue (#448EE4) |
| Black text | 6.17:1 |
| White text | 3.40:1 |
Values
| HEX | #2591DD |
| RGB | rgb(37, 145, 221) |
| HSL | hsl(205, 73%, 51%) |
| OKLCH | oklch(63.5% 0.147 245.3) |
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 #2591DD | 3.40:1 | AA large text | Lc -66.5 | Content text, not long reading |
| Black text on #2591DD | 6.17:1 | AA | Lc 43.0 | Non-text elements, placeholder text |
| #2591DD text on white | 3.40:1 | AA large text | Lc 61.0 | Content text, not long reading |
| #2591DD text on black | 6.17:1 | AA | Lc -40.7 | 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
#F0F6FC
oklch(97% 0.01 247.9)
-
Step 100
100
#DFECF7
oklch(93.7% 0.02 243.4)
-
Step 200
200
#C4DDF2
oklch(88.6% 0.039 243.5)
-
Step 300
300
#9AC6ED
oklch(80.9% 0.072 245.6)
-
Step 400
400
#5EA7E4
oklch(70.6% 0.116 245.7)
-
Step 500
500 (this color)
#2591DD
oklch(63.5% 0.147 245.3)
-
Step 600
600
#0079BF
oklch(55.7% 0.14 245)
-
Step 700
700
#0065A2
oklch(49% 0.125 245.5)
-
Step 800
800
#005386
oklch(42.8% 0.108 245.3)
-
Step 900
900
#004570
oklch(37.7% 0.095 244.9)
-
Step 950
950
#062942
oklch(27.1% 0.061 244.7)
#2591DD 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) | #6D94E0 | 0.060 |
| Deuteranopia (no green cones) | #5384DC | 0.043 |
| Tritanopia (no blue cones) | #00A4AD | 0.103 |
| Achromatopsia (no color) | #8B8B8B | 0.147 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2591DD
#2591DD
oklch(63.5% 0.147 245.3)
- #C47500
#C47500
oklch(63.4% 0.142 65)
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 #2591DD, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Sky Blue #448EE4 ΔE 0.023
- Water Blue #0E87CC ΔE 0.037
- Chefchaouen Blue #4895EF ΔE 0.038
- Dodger Blue #1E90FF ΔE 0.052
- Cornflower Blue #6495ED ΔE 0.057
- Soft Blue #6488EA ΔE 0.058
- Cool Blue #4984B8 ΔE 0.060
- Faded Blue #658CBB ΔE 0.066
Use #2591DD 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.