#397AB1
Closest named color: Flat Blue (#3C73A8). oklch(56.2% 0.108 246.8), rgb(57, 122, 177).
Aa
Black text reads best on this color (4.59:1).
About this color
#397AB1 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 56%, its chroma 0.108 and its hue 247°. Its hue sits on the cool side of the wheel. The nearest named color is Flat Blue (#3C73A8), ΔE 0.022 away. Black text reads best on it, at 4.59:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.108) |
| Temperature | cool |
| Nearest name | Flat Blue (#3C73A8) |
| Black text | 4.59:1 |
| White text | 4.57:1 |
Values
| HEX | #397AB1 |
| RGB | rgb(57, 122, 177) |
| HSL | hsl(208, 51%, 46%) |
| OKLCH | oklch(56.2% 0.108 246.8) |
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 #397AB1 | 4.57:1 | AA | Lc -77.0 | Fine for body text |
| Black text on #397AB1 | 4.59:1 | AA | Lc 32.6 | Non-text elements, placeholder text |
| #397AB1 text on white | 4.57:1 | AA | Lc 71.5 | Content text, not long reading |
| #397AB1 text on black | 4.59:1 | AA | Lc -30.2 | 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
#F2F6FA
oklch(97.1% 0.007 247.9)
-
Step 100
100
#E3EBF3
oklch(93.6% 0.014 248)
-
Step 200
200
#CBDBEA
oklch(88.4% 0.027 246.4)
-
Step 300
300
#A8C4DF
oklch(80.8% 0.049 247.5)
-
Step 400
400
#78A6CF
oklch(70.8% 0.078 246.1)
-
Step 500
500
#548FC2
oklch(63.1% 0.099 246.3)
-
Step 600
600 (this color)
#397AB1
oklch(56.2% 0.108 246.8)
-
Step 700
700
#296596
oklch(49.1% 0.1 246.5)
-
Step 800
800
#23527A
oklch(42.6% 0.084 247.1)
-
Step 900
900
#224462
oklch(37.6% 0.065 247.2)
-
Step 950
950
#152839
oklch(26.9% 0.04 246.9)
#397AB1 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) | #627CB3 | 0.044 |
| Deuteranopia (no green cones) | #5170B0 | 0.034 |
| Tritanopia (no blue cones) | #00878D | 0.082 |
| Achromatopsia (no color) | #767676 | 0.108 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #397AB1
#397AB1
oklch(56.2% 0.108 246.8)
- #9F6723
#9F6723
oklch(56.2% 0.108 66.9)
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 #397AB1, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Flat Blue #3C73A8 ΔE 0.022
- Nice Blue #107AB0 ΔE 0.022
- Windows Blue #3778BF ΔE 0.024
- Steel Blue #4682B4 ΔE 0.027
- Cerulean #457B9D ΔE 0.033
- Dull Blue #49759C ΔE 0.034
- Muted Blue #3B719F ΔE 0.034
- Cool Blue #4984B8 ΔE 0.034
Use #397AB1 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.