#378DB9
Closest named color: Blue NCS (#118AB2). oklch(61.1% 0.105 234.7), rgb(55, 141, 185).
Aa
Black text reads best on this color (5.67:1).
About this color
#378DB9 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 61%, its chroma 0.105 and its hue 235°. Its hue sits on the cool side of the wheel. The nearest named color is Blue NCS (#118AB2), ΔE 0.024 away. Black text reads best on it, at 5.67:1.
| Hue family | Blues |
| Lightness | medium-dark (61%) |
| Chroma | moderately saturated (0.105) |
| Temperature | cool |
| Nearest name | Blue NCS (#118AB2) |
| Black text | 5.67:1 |
| White text | 3.70:1 |
Values
| HEX | #378DB9 |
| RGB | rgb(55, 141, 185) |
| HSL | hsl(200, 54%, 47%) |
| OKLCH | oklch(61.1% 0.105 234.7) |
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 #378DB9 | 3.70:1 | AA large text | Lc -69.8 | Content text, not long reading |
| Black text on #378DB9 | 5.67:1 | AA | Lc 39.8 | Non-text elements, placeholder text |
| #378DB9 text on white | 3.70:1 | AA large text | Lc 64.3 | Content text, not long reading |
| #378DB9 text on black | 5.67:1 | 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
#F1F6F9
oklch(97% 0.007 233.6)
-
Step 100
100
#E1ECF2
oklch(93.7% 0.014 231.2)
-
Step 200
200
#C8DDEA
oklch(88.6% 0.029 234.9)
-
Step 300
300
#A1C7DD
oklch(80.9% 0.051 233.6)
-
Step 400
400
#6BA9CD
oklch(70.6% 0.083 235.1)
-
Step 500
500 (this color)
#378DB9
oklch(61.1% 0.105 234.7)
-
Step 600
600
#0E7DAC
oklch(55.7% 0.114 234.6)
-
Step 700
700
#006992
oklch(49.1% 0.103 234.3)
-
Step 800
800
#065678
oklch(42.8% 0.088 234.6)
-
Step 900
900
#134760
oklch(37.7% 0.068 234)
-
Step 950
950
#0E2A38
oklch(27.1% 0.042 233.2)
#378DB9 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) | #788CBB | 0.065 |
| Deuteranopia (no green cones) | #667FB8 | 0.055 |
| Tritanopia (no blue cones) | #00999C | 0.068 |
| Achromatopsia (no color) | #858585 | 0.105 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #378DB9
#378DB9
oklch(61.1% 0.105 234.7)
- #B47142
#B47142
oklch(61.1% 0.105 54.4)
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 #378DB9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Blue NCS #118AB2 ΔE 0.024
- Cool Blue #4984B8 ΔE 0.027
- Steel Blue #4682B4 ΔE 0.031
- Off Blue #5684AE ΔE 0.033
- Dusty Blue #5A86AD ΔE 0.034
- Water Blue #0E87CC ΔE 0.041
- Faded Blue #658CBB ΔE 0.042
- Teal Blue #01889F ΔE 0.049
Use #378DB9 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.