#397FA9
Closest named color: Cerulean (#457B9D). oklch(57% 0.095 238), rgb(57, 127, 169).
Aa
Black text reads best on this color (4.78:1).
About this color
#397FA9 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 57%, its chroma 0.095 and its hue 238°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean (#457B9D), ΔE 0.020 away. Black text reads best on it, at 4.78:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.095) |
| Temperature | cool |
| Nearest name | Cerulean (#457B9D) |
| Black text | 4.78:1 |
| White text | 4.39:1 |
Values
| HEX | #397FA9 |
| RGB | rgb(57, 127, 169) |
| HSL | hsl(203, 50%, 44%) |
| OKLCH | oklch(57% 0.095 238) |
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 #397FA9 | 4.39:1 | AA large text | Lc -75.7 | Fine for body text |
| Black text on #397FA9 | 4.78:1 | AA | Lc 33.9 | Non-text elements, placeholder text |
| #397FA9 text on white | 4.39:1 | AA large text | Lc 70.2 | Content text, not long reading |
| #397FA9 text on black | 4.78:1 | AA | Lc -31.5 | 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
#F2F6F9
oklch(97.1% 0.006 239.8)
-
Step 100
100
#E3EBF1
oklch(93.6% 0.012 239.9)
-
Step 200
200
#CBDCE7
oklch(88.5% 0.024 236)
-
Step 300
300
#A8C5DA
oklch(80.9% 0.043 239.6)
-
Step 400
400
#78A7C7
oklch(70.7% 0.069 238.8)
-
Step 500
500
#5391B8
oklch(63.1% 0.087 237.9)
-
Step 600
600 (this color)
#397FA9
oklch(57% 0.095 238)
-
Step 700
700
#26678D
oklch(49% 0.089 238.3)
-
Step 800
800
#225472
oklch(42.6% 0.073 238.2)
-
Step 900
900
#21465C
oklch(37.7% 0.057 237)
-
Step 950
950
#142936
oklch(27% 0.036 237.4)
#397FA9 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) | #6B7FAB | 0.054 |
| Deuteranopia (no green cones) | #5C73A8 | 0.046 |
| Tritanopia (no blue cones) | #008A8D | 0.067 |
| Achromatopsia (no color) | #787878 | 0.095 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #397FA9
#397FA9
oklch(57% 0.095 238)
- #A1683B
#A1683B
oklch(56.9% 0.095 57.6)
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 #397FA9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean #457B9D ΔE 0.020
- Steel Blue #4682B4 ΔE 0.022
- Stormy Blue #507B9C ΔE 0.027
- Cool Blue #4984B8 ΔE 0.031
- Nice Blue #107AB0 ΔE 0.031
- Dull Blue #49759C ΔE 0.031
- Blue NCS #118AB2 ΔE 0.033
- Off Blue #5684AE ΔE 0.034
Use #397FA9 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.