#2166CD
Closest named color: Royal Blue (#4169E1). oklch(52.8% 0.174 259), rgb(33, 102, 205).
Aa
White text reads best on this color (5.45:1).
About this color
#2166CD is a medium-dark, vivid blue. In OKLCH its lightness is 53%, its chroma 0.174 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.042 away. White text reads best on it, at 5.45:1.
| Hue family | Blues |
| Lightness | medium-dark (53%) |
| Chroma | vivid (0.174) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 3.84:1 |
| White text | 5.45:1 |
Values
| HEX | #2166CD |
| RGB | rgb(33, 102, 205) |
| HSL | hsl(216, 72%, 47%) |
| OKLCH | oklch(52.8% 0.174 259) |
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 #2166CD | 5.45:1 | AA | Lc -82.0 | Fine for body text |
| Black text on #2166CD | 3.84:1 | AA large text | Lc 27.4 | Dividers and decoration only |
| #2166CD text on white | 5.45:1 | AA | Lc 76.7 | Fine for body text |
| #2166CD text on black | 3.84:1 | AA large text | Lc -25.1 | 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 600.
-
Step 50
50
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E1EBF9
oklch(93.7% 0.022 256.7)
-
Step 200
200
#C8DAF6
oklch(88.4% 0.043 259.2)
-
Step 300
300
#A2C2F4
oklch(80.8% 0.079 259.2)
-
Step 400
400
#70A1EE
oklch(70.7% 0.125 259.1)
-
Step 500
500
#4987E8
oklch(63% 0.16 259.1)
-
Step 600
600 (this color)
#2166CD
oklch(52.8% 0.174 259)
-
Step 700
700
#1D5CBA
oklch(49.1% 0.162 258.9)
-
Step 800
800
#1A4C97
oklch(42.8% 0.134 258.8)
-
Step 900
900
#1C4078
oklch(37.7% 0.104 259.1)
-
Step 950
950
#112646
oklch(27% 0.066 258.6)
#2166CD 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) | #2372D1 | 0.032 |
| Deuteranopia (no green cones) | #0062CB | 0.018 |
| Tritanopia (no blue cones) | #007F90 | 0.132 |
| Achromatopsia (no color) | #696969 | 0.174 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2166CD
#2166CD
oklch(52.8% 0.174 259)
- #8D6200
#8D6200
oklch(52.8% 0.11 78.7)
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 #2166CD, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.042
- Mid Blue #276AB3 ΔE 0.044
- Cerulean Blue #056EEE ΔE 0.053
- Azul #1D5DEC ΔE 0.053
- Warm Blue #4B57DB ΔE 0.053
- Neon Blue #4361EE ΔE 0.060
- French Blue #436BAD ΔE 0.060
- Windows Blue #3778BF ΔE 0.061
Use #2166CD 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.