#2173A4
Closest named color: Ocean Blue (#03719C). oklch(53.1% 0.108 240.3), rgb(33, 115, 164).
Aa
White text reads best on this color (5.18:1).
About this color
#2173A4 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 53%, its chroma 0.108 and its hue 240°. Its hue sits on the cool side of the wheel. The nearest named color is Ocean Blue (#03719C), ΔE 0.018 away. White text reads best on it, at 5.18:1.
| Hue family | Blues |
| Lightness | medium-dark (53%) |
| Chroma | moderately saturated (0.108) |
| Temperature | cool |
| Nearest name | Ocean Blue (#03719C) |
| Black text | 4.05:1 |
| White text | 5.18:1 |
Values
| HEX | #2173A4 |
| RGB | rgb(33, 115, 164) |
| HSL | hsl(202, 66%, 39%) |
| OKLCH | oklch(53.1% 0.108 240.3) |
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 #2173A4 | 5.18:1 | AA | Lc -80.7 | Fine for body text |
| Black text on #2173A4 | 4.05:1 | AA large text | Lc 28.8 | Dividers and decoration only |
| #2173A4 text on white | 5.18:1 | AA | Lc 75.3 | Fine for body text |
| #2173A4 text on black | 4.05:1 | AA large text | Lc -26.4 | 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
#F2F6F9
oklch(97.1% 0.006 239.8)
-
Step 100
100
#E2EBF2
oklch(93.5% 0.014 241)
-
Step 200
200
#CADCEA
oklch(88.5% 0.027 241.2)
-
Step 300
300
#A5C5DD
oklch(80.8% 0.048 240.6)
-
Step 400
400
#73A7CD
oklch(70.6% 0.078 241)
-
Step 500
500
#4C91C0
oklch(63.1% 0.1 240.6)
-
Step 600
600 (this color)
#2173A4
oklch(53.1% 0.108 240.3)
-
Step 700
700
#1C6794
oklch(49.1% 0.101 240.5)
-
Step 800
800
#1A5478
oklch(42.7% 0.084 240.5)
-
Step 900
900
#1D4661
oklch(37.8% 0.065 240.4)
-
Step 950
950
#122939
oklch(27% 0.042 241)
#2173A4 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) | #5C74A6 | 0.055 |
| Deuteranopia (no green cones) | #4A68A3 | 0.043 |
| Tritanopia (no blue cones) | #007F84 | 0.072 |
| Achromatopsia (no color) | #6D6D6D | 0.108 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2173A4
#2173A4
oklch(53.1% 0.108 240.3)
- #995B20
#995B20
oklch(53.1% 0.108 59.9)
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 #2173A4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Ocean Blue #03719C ΔE 0.018
- Muted Blue #3B719F ΔE 0.019
- Flat Blue #3C73A8 ΔE 0.021
- Nice Blue #107AB0 ΔE 0.024
- Sea Blue #047495 ΔE 0.028
- Dull Blue #49759C ΔE 0.035
- French Blue #436BAD ΔE 0.038
- Mid Blue #276AB3 ΔE 0.039
Use #2173A4 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.