#2173CC
Closest named color: Windows Blue (#3778BF). oklch(55.5% 0.157 254.2), rgb(33, 115, 204).
Aa
White text reads best on this color (4.78:1).
About this color
#2173CC is a medium-dark, vivid blue. In OKLCH its lightness is 56%, its chroma 0.157 and its hue 254°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.030 away. White text reads best on it, at 4.78:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | vivid (0.157) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.38:1 |
| White text | 4.78:1 |
Values
| HEX | #2173CC |
| RGB | rgb(33, 115, 204) |
| HSL | hsl(211, 72%, 46%) |
| OKLCH | oklch(55.5% 0.157 254.2) |
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 #2173CC | 4.78:1 | AA | Lc -78.1 | Fine for body text |
| Black text on #2173CC | 4.38:1 | AA large text | Lc 31.4 | Non-text elements, placeholder text |
| #2173CC text on white | 4.78:1 | AA | Lc 72.7 | Content text, not long reading |
| #2173CC text on black | 4.38:1 | AA large text | Lc -29.0 | 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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF8
oklch(93.6% 0.021 254.9)
-
Step 200
200
#C8DBF3
oklch(88.5% 0.039 254.3)
-
Step 300
300
#A1C4EE
oklch(80.9% 0.071 253.2)
-
Step 400
400
#6EA4E6
oklch(70.8% 0.113 254.1)
-
Step 500
500
#448BDE
oklch(63% 0.144 254)
-
Step 600
600 (this color)
#2173CC
oklch(55.5% 0.157 254.2)
-
Step 700
700
#1260B1
oklch(49.1% 0.147 254.2)
-
Step 800
800
#144F8F
oklch(42.7% 0.121 254.1)
-
Step 900
900
#184272
oklch(37.7% 0.095 254)
-
Step 950
950
#102743
oklch(27% 0.06 254.6)
#2173CC 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) | #457BCF | 0.037 |
| Deuteranopia (no green cones) | #216BCA | 0.022 |
| Tritanopia (no blue cones) | #008895 | 0.118 |
| Achromatopsia (no color) | #727272 | 0.157 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2173CC
#2173CC
oklch(55.5% 0.157 254.2)
- #9B6700
#9B6700
oklch(55.5% 0.117 74.4)
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 #2173CC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.030
- Mid Blue #276AB3 ΔE 0.043
- Royal Blue #4169E1 ΔE 0.048
- Nice Blue #107AB0 ΔE 0.052
- French Blue #436BAD ΔE 0.052
- Water Blue #0E87CC ΔE 0.055
- Cerulean Blue #056EEE ΔE 0.055
- Flat Blue #3C73A8 ΔE 0.058
Use #2173CC 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.