#378BB5
Closest named color: Blue NCS (#118AB2). oklch(60.4% 0.102 233.9), rgb(55, 139, 181).
Aa
Black text reads best on this color (5.52:1).
About this color
#378BB5 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 60%, its chroma 0.102 and its hue 234°. Its hue sits on the cool side of the wheel. The nearest named color is Blue NCS (#118AB2), ΔE 0.019 away. Black text reads best on it, at 5.52:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | moderately saturated (0.102) |
| Temperature | cool |
| Nearest name | Blue NCS (#118AB2) |
| Black text | 5.52:1 |
| White text | 3.80:1 |
Values
| HEX | #378BB5 |
| RGB | rgb(55, 139, 181) |
| HSL | hsl(200, 53%, 46%) |
| OKLCH | oklch(60.4% 0.102 233.9) |
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 #378BB5 | 3.80:1 | AA large text | Lc -70.8 | Content text, not long reading |
| Black text on #378BB5 | 5.52:1 | AA | Lc 38.8 | Non-text elements, placeholder text |
| #378BB5 text on white | 3.80:1 | AA large text | Lc 65.3 | Content text, not long reading |
| #378BB5 text on black | 5.52:1 | AA | Lc -36.4 | 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
#F1F6F9
oklch(97% 0.007 233.6)
-
Step 100
100
#E1ECF2
oklch(93.7% 0.014 231.2)
-
Step 200
200
#C8DDE9
oklch(88.6% 0.028 232.7)
-
Step 300
300
#A2C7DC
oklch(81% 0.049 233.1)
-
Step 400
400
#6DA9CB
oklch(70.7% 0.08 234.4)
-
Step 500
500 (this color)
#378BB5
oklch(60.4% 0.102 233.9)
-
Step 600
600
#147DAA
oklch(55.6% 0.111 233.9)
-
Step 700
700
#006992
oklch(49.1% 0.103 234.3)
-
Step 800
800
#0A5676
oklch(42.7% 0.085 233.5)
-
Step 900
900
#15475F
oklch(37.7% 0.066 233.5)
-
Step 950
950
#0E2A38
oklch(27.1% 0.042 233.2)
#378BB5 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) | #778AB7 | 0.065 |
| Deuteranopia (no green cones) | #657DB4 | 0.055 |
| Tritanopia (no blue cones) | #009699 | 0.065 |
| Achromatopsia (no color) | #838383 | 0.102 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #378BB5
#378BB5
oklch(60.4% 0.102 233.9)
- #B17043
#B17043
oklch(60.6% 0.102 54.2)
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 #378BB5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Blue NCS #118AB2 ΔE 0.019
- Cool Blue #4984B8 ΔE 0.025
- Steel Blue #4682B4 ΔE 0.026
- Off Blue #5684AE ΔE 0.030
- Dusty Blue #5A86AD ΔE 0.032
- Teal Blue #01889F ΔE 0.043
- Water Blue #0E87CC ΔE 0.043
- Faded Blue #658CBB ΔE 0.045
Use #378BB5 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.