#377FD8
Closest named color: Water Blue (#0E87CC). oklch(59.6% 0.154 255.4), rgb(55, 127, 216).
Aa
Black text reads best on this color (5.18:1).
About this color
#377FD8 is a medium-dark, vivid blue. In OKLCH its lightness is 60%, its chroma 0.154 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.035 away. Black text reads best on it, at 5.18:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | vivid (0.154) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.18:1 |
| White text | 4.04:1 |
Values
| HEX | #377FD8 |
| RGB | rgb(55, 127, 216) |
| HSL | hsl(213, 67%, 53%) |
| OKLCH | oklch(59.6% 0.154 255.4) |
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 #377FD8 | 4.04:1 | AA large text | Lc -72.8 | Content text, not long reading |
| Black text on #377FD8 | 5.18:1 | AA | Lc 36.8 | Non-text elements, placeholder text |
| #377FD8 text on white | 4.04:1 | AA large text | Lc 67.3 | Content text, not long reading |
| #377FD8 text on black | 5.18:1 | AA | Lc -34.3 | 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 500.
-
Step 50
50
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF9
oklch(93.7% 0.022 256.7)
-
Step 200
200
#C7DBF5
oklch(88.5% 0.042 255)
-
Step 300
300
#A1C3F1
oklch(80.8% 0.075 256.1)
-
Step 400
400
#6CA3EA
oklch(70.7% 0.12 255.3)
-
Step 500
500 (this color)
#377FD8
oklch(59.6% 0.154 255.4)
-
Step 600
600
#1E72D2
oklch(55.7% 0.167 255.3)
-
Step 700
700
#0F5FB6
oklch(49.2% 0.155 255.4)
-
Step 800
800
#114E93
oklch(42.7% 0.128 255.2)
-
Step 900
900
#174175
oklch(37.6% 0.1 255.6)
-
Step 950
950
#0F2745
oklch(27.1% 0.064 255.3)
#377FD8 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) | #5486DC | 0.035 |
| Deuteranopia (no green cones) | #3877D6 | 0.021 |
| Tritanopia (no blue cones) | #0094A1 | 0.118 |
| Achromatopsia (no color) | #7E7E7E | 0.154 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #377FD8
#377FD8
oklch(59.6% 0.154 255.4)
- #AA7200
#AA7200
oklch(59.6% 0.126 74.9)
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 #377FD8, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.035
- Windows Blue #3778BF ΔE 0.040
- Dark Sky Blue #448EE4 ΔE 0.045
- Cool Blue #4984B8 ΔE 0.056
- Soft Blue #6488EA ΔE 0.059
- Steel Blue #4682B4 ΔE 0.059
- Royal Blue #4169E1 ΔE 0.060
- Clear Blue #247AFD ΔE 0.060
Use #377FD8 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.