#378CD3
Closest named color: Water Blue (#0E87CC). oklch(62.2% 0.135 247.5), rgb(55, 140, 211).
Aa
Black text reads best on this color (5.85:1).
About this color
#378CD3 is a medium-light, moderately saturated blue. In OKLCH its lightness is 62%, its chroma 0.135 and its hue 247°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.027 away. Black text reads best on it, at 5.85:1.
| Hue family | Blues |
| Lightness | medium-light (62%) |
| Chroma | moderately saturated (0.135) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.85:1 |
| White text | 3.58:1 |
Values
| HEX | #378CD3 |
| RGB | rgb(55, 140, 211) |
| HSL | hsl(207, 64%, 52%) |
| OKLCH | oklch(62.2% 0.135 247.5) |
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 #378CD3 | 3.58:1 | AA large text | Lc -68.6 | Content text, not long reading |
| Black text on #378CD3 | 5.85:1 | AA | Lc 41.0 | Non-text elements, placeholder text |
| #378CD3 text on white | 3.58:1 | AA large text | Lc 63.1 | Content text, not long reading |
| #378CD3 text on black | 5.85:1 | AA | Lc -38.6 | 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
#C7DCF1
oklch(88.5% 0.037 248.2)
-
Step 300
300
#9FC5EA
oklch(80.9% 0.066 248)
-
Step 400
400
#68A6DF
oklch(70.6% 0.106 247.6)
-
Step 500
500 (this color)
#378CD3
oklch(62.2% 0.135 247.5)
-
Step 600
600
#0577C3
oklch(55.5% 0.146 247.6)
-
Step 700
700
#0064A6
oklch(49.1% 0.131 247.6)
-
Step 800
800
#025289
oklch(42.7% 0.113 247.6)
-
Step 900
900
#11446D
oklch(37.6% 0.088 247.6)
-
Step 950
950
#0C2840
oklch(26.9% 0.056 247.6)
#378CD3 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) | #6B8FD6 | 0.050 |
| Deuteranopia (no green cones) | #5581D2 | 0.036 |
| Tritanopia (no blue cones) | #009DA6 | 0.097 |
| Achromatopsia (no color) | #878787 | 0.135 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #378CD3
#378CD3
oklch(62.2% 0.135 247.5)
- #BB740A
#BB740A
oklch(62.1% 0.134 67.4)
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 #378CD3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.027
- Dark Sky Blue #448EE4 ΔE 0.028
- Cool Blue #4984B8 ΔE 0.042
- Chefchaouen Blue #4895EF ΔE 0.049
- Steel Blue #4682B4 ΔE 0.049
- Faded Blue #658CBB ΔE 0.053
- Blue NCS #118AB2 ΔE 0.056
- Soft Blue #6488EA ΔE 0.057
Use #378CD3 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.