#377FAE
Closest named color: Steel Blue (#4682B4). oklch(57.2% 0.102 240.5), rgb(55, 127, 174).
Aa
Black text reads best on this color (4.80:1).
About this color
#377FAE is a medium-dark, moderately saturated blue. In OKLCH its lightness is 57%, its chroma 0.102 and its hue 241°. Its hue sits on the cool side of the wheel. The nearest named color is Steel Blue (#4682B4), ΔE 0.019 away. Black text reads best on it, at 4.80:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.102) |
| Temperature | cool |
| Nearest name | Steel Blue (#4682B4) |
| Black text | 4.80:1 |
| White text | 4.36:1 |
Values
| HEX | #377FAE |
| RGB | rgb(55, 127, 174) |
| HSL | hsl(204, 52%, 45%) |
| OKLCH | oklch(57.2% 0.102 240.5) |
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 #377FAE | 4.36:1 | AA large text | Lc -75.5 | Fine for body text |
| Black text on #377FAE | 4.80:1 | AA | Lc 34.1 | Non-text elements, placeholder text |
| #377FAE text on white | 4.36:1 | AA large text | Lc 70.0 | Content text, not long reading |
| #377FAE text on black | 4.80:1 | AA | Lc -31.7 | 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
#E2EBF2
oklch(93.5% 0.014 241)
-
Step 200
200
#CBDCE9
oklch(88.6% 0.026 240.7)
-
Step 300
300
#A7C5DC
oklch(80.9% 0.046 241.2)
-
Step 400
400
#76A7CA
oklch(70.7% 0.073 240.2)
-
Step 500
500
#5191BD
oklch(63.2% 0.094 240.5)
-
Step 600
600 (this color)
#377FAE
oklch(57.2% 0.102 240.5)
-
Step 700
700
#246791
oklch(49.2% 0.094 240.4)
-
Step 800
800
#205476
oklch(42.8% 0.079 240.9)
-
Step 900
900
#20465F
oklch(37.8% 0.061 239.9)
-
Step 950
950
#142938
oklch(27.1% 0.039 241.3)
#377FAE 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) | #697FB0 | 0.052 |
| Deuteranopia (no green cones) | #5974AD | 0.042 |
| Tritanopia (no blue cones) | #008B8F | 0.072 |
| Achromatopsia (no color) | #797979 | 0.102 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #377FAE
#377FAE
oklch(57.2% 0.102 240.5)
- #A36833
#A36833
oklch(57.1% 0.102 60.3)
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 #377FAE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Steel Blue #4682B4 ΔE 0.019
- Cool Blue #4984B8 ΔE 0.027
- Cerulean #457B9D ΔE 0.027
- Nice Blue #107AB0 ΔE 0.027
- Blue NCS #118AB2 ΔE 0.033
- Stormy Blue #507B9C ΔE 0.033
- Flat Blue #3C73A8 ΔE 0.034
- Off Blue #5684AE ΔE 0.034
Use #377FAE 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.