#2181C5
Closest named color: Water Blue (#0E87CC). oklch(58.3% 0.134 245.3), rgb(33, 129, 197).
Aa
Black text reads best on this color (5.01:1).
About this color
#2181C5 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.134 and its hue 245°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.018 away. Black text reads best on it, at 5.01:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.134) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.01:1 |
| White text | 4.19:1 |
Values
| HEX | #2181C5 |
| RGB | rgb(33, 129, 197) |
| HSL | hsl(205, 71%, 45%) |
| OKLCH | oklch(58.3% 0.134 245.3) |
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 #2181C5 | 4.19:1 | AA large text | Lc -73.9 | Content text, not long reading |
| Black text on #2181C5 | 5.01:1 | AA | Lc 35.6 | Non-text elements, placeholder text |
| #2181C5 text on white | 4.19:1 | AA large text | Lc 68.4 | Content text, not long reading |
| #2181C5 text on black | 5.01:1 | AA | Lc -33.2 | 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
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E1EBF5
oklch(93.5% 0.017 248)
-
Step 200
200
#C8DCEE
oklch(88.5% 0.033 245.3)
-
Step 300
300
#A1C5E6
oklch(80.8% 0.061 246.3)
-
Step 400
400
#6BA7D9
oklch(70.7% 0.097 244.9)
-
Step 500
500
#3F90CF
oklch(63.2% 0.123 245.1)
-
Step 600
600 (this color)
#2181C5
oklch(58.3% 0.134 245.3)
-
Step 700
700
#0065A2
oklch(49% 0.125 245.5)
-
Step 800
800
#095383
oklch(42.7% 0.103 244.9)
-
Step 900
900
#144569
oklch(37.7% 0.08 244.8)
-
Step 950
950
#0E293E
oklch(27.2% 0.051 244.9)
#2181C5 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) | #6184C8 | 0.055 |
| Deuteranopia (no green cones) | #4975C4 | 0.040 |
| Tritanopia (no blue cones) | #00929A | 0.095 |
| Achromatopsia (no color) | #7C7C7C | 0.134 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2181C5
#2181C5
oklch(58.3% 0.134 245.3)
- #AF6800
#AF6800
oklch(58.3% 0.131 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 #2181C5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.018
- Windows Blue #3778BF ΔE 0.026
- Steel Blue #4682B4 ΔE 0.035
- Cool Blue #4984B8 ΔE 0.036
- Nice Blue #107AB0 ΔE 0.037
- Blue NCS #118AB2 ΔE 0.044
- Flat Blue #3C73A8 ΔE 0.053
- Off Blue #5684AE ΔE 0.055
Use #2181C5 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.