#378BD8
Closest named color: Dark Sky Blue (#448EE4). oklch(62.3% 0.141 249.6), rgb(55, 139, 216).
Aa
Black text reads best on this color (5.84:1).
About this color
#378BD8 is a medium-light, vivid blue. In OKLCH its lightness is 62%, its chroma 0.141 and its hue 250°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Sky Blue (#448EE4), ΔE 0.022 away. Black text reads best on it, at 5.84:1.
| Hue family | Blues |
| Lightness | medium-light (62%) |
| Chroma | vivid (0.141) |
| Temperature | cool |
| Nearest name | Dark Sky Blue (#448EE4) |
| Black text | 5.84:1 |
| White text | 3.59:1 |
Values
| HEX | #378BD8 |
| RGB | rgb(55, 139, 216) |
| HSL | hsl(209, 67%, 53%) |
| OKLCH | oklch(62.3% 0.141 249.6) |
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 #378BD8 | 3.59:1 | AA large text | Lc -68.6 | Content text, not long reading |
| Black text on #378BD8 | 5.84:1 | AA | Lc 40.9 | Non-text elements, placeholder text |
| #378BD8 text on white | 3.59:1 | AA large text | Lc 63.1 | Content text, not long reading |
| #378BD8 text on black | 5.84:1 | AA | Lc -38.5 | 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 500.
-
Step 50
50
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E0EBF7
oklch(93.5% 0.02 250.4)
-
Step 200
200
#C7DCF2
oklch(88.6% 0.038 249.5)
-
Step 300
300
#9FC5EC
oklch(80.9% 0.069 249.4)
-
Step 400
400
#68A6E3
oklch(70.8% 0.111 249.3)
-
Step 500
500 (this color)
#378BD8
oklch(62.3% 0.141 249.6)
-
Step 600
600
#0676C8
oklch(55.6% 0.153 249.5)
-
Step 700
700
#0063AA
oklch(49.1% 0.137 249.4)
-
Step 800
800
#02518C
oklch(42.7% 0.118 249.4)
-
Step 900
900
#114470
oklch(37.8% 0.092 249.2)
-
Step 950
950
#0C2842
oklch(27.1% 0.059 249.5)
#378BD8 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) | #678FDB | 0.047 |
| Deuteranopia (no green cones) | #5080D6 | 0.033 |
| Tritanopia (no blue cones) | #009DA7 | 0.104 |
| Achromatopsia (no color) | #878787 | 0.141 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #378BD8
#378BD8
oklch(62.3% 0.141 249.6)
- #BA7600
#BA7600
oklch(62.3% 0.135 69.9)
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 #378BD8, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Sky Blue #448EE4 ΔE 0.022
- Water Blue #0E87CC ΔE 0.029
- Chefchaouen Blue #4895EF ΔE 0.044
- Cool Blue #4984B8 ΔE 0.049
- Soft Blue #6488EA ΔE 0.051
- Steel Blue #4682B4 ΔE 0.055
- Dodger Blue #1E90FF ΔE 0.058
- Faded Blue #658CBB ΔE 0.059
Use #378BD8 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.