#3173A5
Closest named color: Flat Blue (#3C73A8). oklch(53.6% 0.103 244.5), rgb(49, 115, 165).
Aa
White text reads best on this color (5.08:1).
About this color
#3173A5 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 54%, its chroma 0.103 and its hue 244°. Its hue sits on the cool side of the wheel. The nearest named color is Flat Blue (#3C73A8), ΔE 0.011 away. White text reads best on it, at 5.08:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | moderately saturated (0.103) |
| Temperature | cool |
| Nearest name | Flat Blue (#3C73A8) |
| Black text | 4.12:1 |
| White text | 5.08:1 |
Values
| HEX | #3173A5 |
| RGB | rgb(49, 115, 165) |
| HSL | hsl(206, 54%, 42%) |
| OKLCH | oklch(53.6% 0.103 244.5) |
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 #3173A5 | 5.08:1 | AA | Lc -80.2 | Fine for body text |
| Black text on #3173A5 | 4.12:1 | AA large text | Lc 29.2 | Dividers and decoration only |
| #3173A5 text on white | 5.08:1 | AA | Lc 74.9 | Content text, not long reading |
| #3173A5 text on black | 4.12:1 | AA large text | Lc -26.9 | 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
#E3EBF2
oklch(93.6% 0.013 244.3)
-
Step 200
200
#CCDBE9
oklch(88.4% 0.025 246.2)
-
Step 300
300
#A8C5DD
oklch(81% 0.046 243.3)
-
Step 400
400
#79A6CC
oklch(70.7% 0.074 244.6)
-
Step 500
500
#558FBF
oklch(63% 0.095 245.1)
-
Step 600
600 (this color)
#3173A5
oklch(53.6% 0.103 244.5)
-
Step 700
700
#296693
oklch(49.2% 0.095 244)
-
Step 800
800
#245377
oklch(42.7% 0.079 244.4)
-
Step 900
900
#224560
oklch(37.7% 0.062 243.8)
-
Step 950
950
#152838
oklch(26.9% 0.039 245.4)
#3173A5 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) | #5C74A7 | 0.045 |
| Deuteranopia (no green cones) | #4C69A4 | 0.035 |
| Tritanopia (no blue cones) | #007F85 | 0.074 |
| Achromatopsia (no color) | #6E6E6E | 0.103 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3173A5
#3173A5
oklch(53.6% 0.103 244.5)
- #965F23
#965F23
oklch(53.5% 0.103 64.3)
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 #3173A5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Flat Blue #3C73A8 ΔE 0.011
- Muted Blue #3B719F ΔE 0.012
- Nice Blue #107AB0 ΔE 0.025
- Dull Blue #49759C ΔE 0.027
- Ocean Blue #03719C ΔE 0.027
- French Blue #436BAD ΔE 0.032
- Sea Blue #047495 ΔE 0.035
- Cerulean #457B9D ΔE 0.036
Use #3173A5 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.