#3973A7
Closest named color: Flat Blue (#3C73A8). oklch(54% 0.102 247.9), rgb(57, 115, 167).
Aa
White text reads best on this color (5.01:1).
About this color
#3973A7 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 54%, its chroma 0.102 and its hue 248°. Its hue sits on the cool side of the wheel. The nearest named color is Flat Blue (#3C73A8), ΔE 0.003 away. White text reads best on it, at 5.01:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | moderately saturated (0.102) |
| Temperature | cool |
| Nearest name | Flat Blue (#3C73A8) |
| Black text | 4.18:1 |
| White text | 5.01:1 |
Values
| HEX | #3973A7 |
| RGB | rgb(57, 115, 167) |
| HSL | hsl(208, 49%, 44%) |
| OKLCH | oklch(54% 0.102 247.9) |
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 #3973A7 | 5.01:1 | AA | Lc -79.9 | Fine for body text |
| Black text on #3973A7 | 4.18:1 | AA large text | Lc 29.6 | Dividers and decoration only |
| #3973A7 text on white | 5.01:1 | AA | Lc 74.5 | Content text, not long reading |
| #3973A7 text on black | 4.18:1 | AA large text | Lc -27.2 | 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
#E3EBF3
oklch(93.6% 0.014 248)
-
Step 200
200
#CCDBEA
oklch(88.5% 0.026 248.1)
-
Step 300
300
#AAC4DD
oklch(80.9% 0.045 247.3)
-
Step 400
400
#7CA5CD
oklch(70.7% 0.074 248.3)
-
Step 500
500
#598EC0
oklch(63% 0.095 248.2)
-
Step 600
600 (this color)
#3973A7
oklch(54% 0.102 247.9)
-
Step 700
700
#2F6494
oklch(49% 0.096 248.3)
-
Step 800
800
#285278
oklch(42.7% 0.079 248)
-
Step 900
900
#254461
oklch(37.7% 0.062 248.3)
-
Step 950
950
#162839
oklch(27% 0.04 248.2)
#3973A7 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) | #5C75A9 | 0.039 |
| Deuteranopia (no green cones) | #4D6AA6 | 0.030 |
| Tritanopia (no blue cones) | #007F85 | 0.078 |
| Achromatopsia (no color) | #6F6F6F | 0.102 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3973A7
#3973A7
oklch(54% 0.102 247.9)
- #956222
#956222
oklch(54% 0.102 68.1)
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 #3973A7, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Flat Blue #3C73A8 ΔE 0.003
- Muted Blue #3B719F ΔE 0.013
- Dull Blue #49759C ΔE 0.025
- Nice Blue #107AB0 ΔE 0.027
- French Blue #436BAD ΔE 0.027
- Cerulean #457B9D ΔE 0.034
- Ocean Blue #03719C ΔE 0.035
- Windows Blue #3778BF ΔE 0.038
Use #3973A7 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.