#2171F0
Closest named color: Cerulean Blue (#056EEE). oklch(57.7% 0.206 259.9), rgb(33, 113, 240).
Aa
Black text reads best on this color (4.68:1).
About this color
#2171F0 is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.206 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean Blue (#056EEE), ΔE 0.013 away. Black text reads best on it, at 4.68:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.206) |
| Temperature | cool |
| Nearest name | Cerulean Blue (#056EEE) |
| Black text | 4.68:1 |
| White text | 4.48:1 |
Values
| HEX | #2171F0 |
| RGB | rgb(33, 113, 240) |
| HSL | hsl(217, 87%, 54%) |
| OKLCH | oklch(57.7% 0.206 259.9) |
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 #2171F0 | 4.48:1 | AA large text | Lc -75.9 | Fine for body text |
| Black text on #2171F0 | 4.68:1 | AA | Lc 33.7 | Non-text elements, placeholder text |
| #2171F0 text on white | 4.48:1 | AA large text | Lc 70.4 | Content text, not long reading |
| #2171F0 text on black | 4.68:1 | AA | Lc -31.2 | 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
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E0EBFC
oklch(93.7% 0.026 259)
-
Step 200
200
#C6DAFC
oklch(88.4% 0.052 261.1)
-
Step 300
300
#9EC2FD
oklch(80.9% 0.093 260.1)
-
Step 400
400
#68A0FC
oklch(70.8% 0.148 259.9)
-
Step 500
500
#3D84FA
oklch(63.1% 0.19 260)
-
Step 600
600 (this color)
#2171F0
oklch(57.7% 0.206 259.9)
-
Step 700
700
#0958CA
oklch(49.2% 0.19 259.7)
-
Step 800
800
#0E48A4
oklch(42.7% 0.16 260.1)
-
Step 900
900
#143E82
oklch(37.8% 0.124 259.8)
-
Step 950
950
#0D254C
oklch(27% 0.078 259.7)
#2171F0 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) | #0081F4 | 0.039 |
| Deuteranopia (no green cones) | #006EEE | 0.014 |
| Tritanopia (no blue cones) | #0091A6 | 0.158 |
| Achromatopsia (no color) | #777777 | 0.206 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2171F0
#2171F0
oklch(57.7% 0.206 259.9)
- #9E7000
#9E7000
oklch(57.7% 0.12 80)
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 #2171F0, closest first.
No curated palette has a color within ΔE 0.04 of #2171F0.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean Blue #056EEE ΔE 0.013
- Clear Blue #247AFD ΔE 0.029
- Royal Blue #4169E1 ΔE 0.033
- Bright Blue #0165FC ΔE 0.037
- Neon Blue #4361EE ΔE 0.040
- Azul #1D5DEC ΔE 0.048
- Warm Blue #4B57DB ΔE 0.070
- Cornflower #6A79F7 ΔE 0.074
Use #2171F0 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.