#378ACC
Closest named color: Water Blue (#0E87CC). oklch(61.4% 0.128 246.2), rgb(55, 138, 204).
Aa
Black text reads best on this color (5.66:1).
About this color
#378ACC is a medium-dark, moderately saturated blue. In OKLCH its lightness is 61%, its chroma 0.128 and its hue 246°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.021 away. Black text reads best on it, at 5.66:1.
| Hue family | Blues |
| Lightness | medium-dark (61%) |
| Chroma | moderately saturated (0.128) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.66:1 |
| White text | 3.70:1 |
Values
| HEX | #378ACC |
| RGB | rgb(55, 138, 204) |
| HSL | hsl(207, 59%, 51%) |
| OKLCH | oklch(61.4% 0.128 246.2) |
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 #378ACC | 3.70:1 | AA large text | Lc -69.8 | Content text, not long reading |
| Black text on #378ACC | 5.66:1 | AA | Lc 39.8 | Non-text elements, placeholder text |
| #378ACC text on white | 3.70:1 | AA large text | Lc 64.3 | Content text, not long reading |
| #378ACC text on black | 5.66:1 | AA | Lc -37.4 | 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
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E0EBF6
oklch(93.5% 0.019 248)
-
Step 200
200
#C7DCEF
oklch(88.5% 0.035 245.5)
-
Step 300
300
#A0C5E7
oklch(80.8% 0.062 246.4)
-
Step 400
400
#6AA7DB
oklch(70.8% 0.099 245.5)
-
Step 500
500 (this color)
#378ACC
oklch(61.4% 0.128 246.2)
-
Step 600
600
#0E78BF
oklch(55.5% 0.139 246.3)
-
Step 700
700
#0065A3
oklch(49.1% 0.126 245.9)
-
Step 800
800
#065285
oklch(42.5% 0.107 246.3)
-
Step 900
900
#13456B
oklch(37.8% 0.083 245.9)
-
Step 950
950
#0D283F
oklch(26.9% 0.054 247.3)
#378ACC 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) | #6C8CCF | 0.052 |
| Deuteranopia (no green cones) | #577ECB | 0.039 |
| Tritanopia (no blue cones) | #009AA2 | 0.092 |
| Achromatopsia (no color) | #858585 | 0.128 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #378ACC
#378ACC
oklch(61.4% 0.128 246.2)
- #B7721A
#B7721A
oklch(61.3% 0.128 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 #378ACC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.021
- Cool Blue #4984B8 ΔE 0.032
- Steel Blue #4682B4 ΔE 0.038
- Dark Sky Blue #448EE4 ΔE 0.039
- Blue NCS #118AB2 ΔE 0.046
- Off Blue #5684AE ΔE 0.049
- Faded Blue #658CBB ΔE 0.049
- Windows Blue #3778BF ΔE 0.051
Use #378ACC 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.