#377DC3
Closest named color: Windows Blue (#3778BF). oklch(57.9% 0.129 251), rgb(55, 125, 195).
Aa
Black text reads best on this color (4.88:1).
About this color
#377DC3 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.129 and its hue 251°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.014 away. Black text reads best on it, at 4.88:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.129) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.88:1 |
| White text | 4.29:1 |
Values
| HEX | #377DC3 |
| RGB | rgb(55, 125, 195) |
| HSL | hsl(210, 56%, 49%) |
| OKLCH | oklch(57.9% 0.129 251) |
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 #377DC3 | 4.29:1 | AA large text | Lc -74.9 | Content text, not long reading |
| Black text on #377DC3 | 4.88:1 | AA | Lc 34.6 | Non-text elements, placeholder text |
| #377DC3 text on white | 4.29:1 | AA large text | Lc 69.4 | Content text, not long reading |
| #377DC3 text on black | 4.88:1 | AA | Lc -32.2 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E2EBF5
oklch(93.6% 0.017 250.8)
-
Step 200
200
#CADBEE
oklch(88.5% 0.032 251.1)
-
Step 300
300
#A5C4E6
oklch(80.9% 0.059 250.9)
-
Step 400
400
#74A5D9
oklch(70.8% 0.093 250.7)
-
Step 500
500
#4E8DCF
oklch(63.1% 0.12 251.2)
-
Step 600
600 (this color)
#377DC3
oklch(57.9% 0.129 251)
-
Step 700
700
#2263A2
oklch(49.1% 0.12 251.2)
-
Step 800
800
#1E5183
oklch(42.7% 0.099 251)
-
Step 900
900
#1F4369
oklch(37.6% 0.078 251.7)
-
Step 950
950
#13283E
oklch(27.1% 0.049 251.1)
#377DC3 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) | #5D81C6 | 0.040 |
| Deuteranopia (no green cones) | #4974C2 | 0.027 |
| Tritanopia (no blue cones) | #008E97 | 0.098 |
| Achromatopsia (no color) | #7A7A7A | 0.129 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #377DC3
#377DC3
oklch(57.9% 0.129 251)
- #A76B00
#A76B00
oklch(57.8% 0.124 71.1)
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 #377DC3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.014
- Water Blue #0E87CC ΔE 0.030
- Steel Blue #4682B4 ΔE 0.033
- Cool Blue #4984B8 ΔE 0.034
- Nice Blue #107AB0 ΔE 0.038
- Flat Blue #3C73A8 ΔE 0.045
- Off Blue #5684AE ΔE 0.051
- Blue NCS #118AB2 ΔE 0.053
Use #377DC3 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.