#2181E3
Closest named color: Water Blue (#0E87CC). oklch(60.2% 0.171 253.4), rgb(33, 129, 227).
Aa
Black text reads best on this color (5.31:1).
About this color
#2181E3 is a medium-dark, vivid blue. In OKLCH its lightness is 60%, its chroma 0.171 and its hue 253°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.042 away. Black text reads best on it, at 5.31:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | vivid (0.171) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.31:1 |
| White text | 3.95:1 |
Values
| HEX | #2181E3 |
| RGB | rgb(33, 129, 227) |
| HSL | hsl(210, 78%, 51%) |
| OKLCH | oklch(60.2% 0.171 253.4) |
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 #2181E3 | 3.95:1 | AA large text | Lc -71.8 | Content text, not long reading |
| Black text on #2181E3 | 5.31:1 | AA | Lc 37.7 | Non-text elements, placeholder text |
| #2181E3 text on white | 3.95:1 | AA large text | Lc 66.3 | Content text, not long reading |
| #2181E3 text on black | 5.31:1 | AA | Lc -35.3 | 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
#F0F6FD
oklch(97.1% 0.011 252.1)
-
Step 100
100
#DFEBFA
oklch(93.6% 0.024 254)
-
Step 200
200
#C4DCF8
oklch(88.6% 0.047 252.4)
-
Step 300
300
#9BC4F6
oklch(80.9% 0.084 253.7)
-
Step 400
400
#61A4F2
oklch(70.8% 0.134 253.4)
-
Step 500
500 (this color)
#2181E3
oklch(60.2% 0.171 253.4)
-
Step 600
600
#0073D5
oklch(55.7% 0.173 253.3)
-
Step 700
700
#0060B4
oklch(49.1% 0.153 253.4)
-
Step 800
800
#004E95
oklch(42.6% 0.134 253.6)
-
Step 900
900
#07417B
oklch(37.6% 0.113 253.8)
-
Step 950
950
#082748
oklch(27.1% 0.071 253.2)
#2181E3 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) | #4E89E7 | 0.041 |
| Deuteranopia (no green cones) | #2678E1 | 0.023 |
| Tritanopia (no blue cones) | #0099A7 | 0.128 |
| Achromatopsia (no color) | #808080 | 0.171 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2181E3
#2181E3
oklch(60.2% 0.171 253.4)
- #AE7300
#AE7300
oklch(60.3% 0.128 73.6)
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 #2181E3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.042
- Dark Sky Blue #448EE4 ΔE 0.045
- Clear Blue #247AFD ΔE 0.045
- Dodger Blue #1E90FF ΔE 0.054
- Cerulean Blue #056EEE ΔE 0.056
- Windows Blue #3778BF ΔE 0.056
- Royal Blue #4169E1 ΔE 0.061
- Soft Blue #6488EA ΔE 0.061
Use #2181E3 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.