#378BDE
Closest named color: Dark Sky Blue (#448EE4). oklch(62.6% 0.149 251.3), rgb(55, 139, 222).
Aa
Black text reads best on this color (5.91:1).
About this color
#378BDE is a medium-light, vivid blue. In OKLCH its lightness is 63%, its chroma 0.149 and its hue 251°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Sky Blue (#448EE4), ΔE 0.016 away. Black text reads best on it, at 5.91:1.
| Hue family | Blues |
| Lightness | medium-light (63%) |
| Chroma | vivid (0.149) |
| Temperature | cool |
| Nearest name | Dark Sky Blue (#448EE4) |
| Black text | 5.91:1 |
| White text | 3.55:1 |
Values
| HEX | #378BDE |
| RGB | rgb(55, 139, 222) |
| HSL | hsl(210, 72%, 54%) |
| OKLCH | oklch(62.6% 0.149 251.3) |
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 #378BDE | 3.55:1 | AA large text | Lc -68.2 | Content text, not long reading |
| Black text on #378BDE | 5.91:1 | AA | Lc 41.3 | Non-text elements, placeholder text |
| #378BDE text on white | 3.55:1 | AA large text | Lc 62.7 | Content text, not long reading |
| #378BDE text on black | 5.91:1 | AA | Lc -38.9 | 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
#E0EBF8
oklch(93.6% 0.021 252.5)
-
Step 200
200
#C6DCF4
oklch(88.6% 0.041 250.6)
-
Step 300
300
#9EC4EF
oklch(80.8% 0.074 251.8)
-
Step 400
400
#67A5E7
oklch(70.7% 0.117 251.2)
-
Step 500
500 (this color)
#378BDE
oklch(62.6% 0.149 251.3)
-
Step 600
600
#0375CD
oklch(55.6% 0.161 251)
-
Step 700
700
#0062AE
oklch(49.1% 0.143 251.1)
-
Step 800
800
#015090
oklch(42.7% 0.125 251.3)
-
Step 900
900
#104373
oklch(37.7% 0.097 251.2)
-
Step 950
950
#0C2843
oklch(27.1% 0.061 250.4)
#378BDE 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) | #6490E1 | 0.044 |
| Deuteranopia (no green cones) | #4B81DC | 0.028 |
| Tritanopia (no blue cones) | #009FAA | 0.112 |
| Achromatopsia (no color) | #888888 | 0.149 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #378BDE
#378BDE
oklch(62.6% 0.149 251.3)
- #BA7800
#BA7800
oklch(62.7% 0.135 71.3)
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 #378BDE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Sky Blue #448EE4 ΔE 0.016
- Water Blue #0E87CC ΔE 0.036
- Chefchaouen Blue #4895EF ΔE 0.039
- Soft Blue #6488EA ΔE 0.046
- Dodger Blue #1E90FF ΔE 0.049
- Cornflower Blue #6495ED ΔE 0.055
- Cool Blue #4984B8 ΔE 0.057
- Steel Blue #4682B4 ΔE 0.064
Use #378BDE 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.