#377FB9
Closest named color: Steel Blue (#4682B4). oklch(57.8% 0.115 246), rgb(55, 127, 185).
Aa
Black text reads best on this color (4.89:1).
About this color
#377FB9 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.115 and its hue 246°. Its hue sits on the cool side of the wheel. The nearest named color is Steel Blue (#4682B4), ΔE 0.018 away. Black text reads best on it, at 4.89:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.115) |
| Temperature | cool |
| Nearest name | Steel Blue (#4682B4) |
| Black text | 4.89:1 |
| White text | 4.28:1 |
Values
| HEX | #377FB9 |
| RGB | rgb(55, 127, 185) |
| HSL | hsl(207, 54%, 47%) |
| OKLCH | oklch(57.8% 0.115 246) |
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 #377FB9 | 4.28:1 | AA large text | Lc -74.9 | Content text, not long reading |
| Black text on #377FB9 | 4.89:1 | AA | Lc 34.7 | Non-text elements, placeholder text |
| #377FB9 text on white | 4.28:1 | AA large text | Lc 69.4 | Content text, not long reading |
| #377FB9 text on black | 4.89:1 | AA | Lc -32.3 | 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
#E2EBF3
oklch(93.6% 0.015 244.7)
-
Step 200
200
#CADCEB
oklch(88.6% 0.028 243.1)
-
Step 300
300
#A6C5E1
oklch(81% 0.052 245.8)
-
Step 400
400
#75A6D1
oklch(70.7% 0.082 245.8)
-
Step 500
500
#4F8FC5
oklch(63% 0.105 246)
-
Step 600
600 (this color)
#377FB9
oklch(57.8% 0.115 246)
-
Step 700
700
#226599
oklch(49.1% 0.106 246.1)
-
Step 800
800
#1E537C
oklch(42.8% 0.088 245.5)
-
Step 900
900
#1F4564
oklch(37.8% 0.069 245.7)
-
Step 950
950
#13283A
oklch(26.9% 0.043 246.2)
#377FB9 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) | #6581BC | 0.048 |
| Deuteranopia (no green cones) | #5375B8 | 0.035 |
| Tritanopia (no blue cones) | #008D94 | 0.084 |
| Achromatopsia (no color) | #7A7A7A | 0.115 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #377FB9
#377FB9
oklch(57.8% 0.115 246)
- #A76A21
#A76A21
oklch(57.8% 0.115 65.9)
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 #377FB9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Steel Blue #4682B4 ΔE 0.018
- Cool Blue #4984B8 ΔE 0.023
- Windows Blue #3778BF ΔE 0.024
- Nice Blue #107AB0 ΔE 0.030
- Water Blue #0E87CC ΔE 0.034
- Flat Blue #3C73A8 ΔE 0.038
- Off Blue #5684AE ΔE 0.038
- Blue NCS #118AB2 ΔE 0.038
Use #377FB9 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.