#378BBC
Closest named color: Cool Blue (#4984B8). oklch(60.8% 0.109 238.1), rgb(55, 139, 188).
Aa
Black text reads best on this color (5.58:1).
About this color
#378BBC is a medium-dark, moderately saturated blue. In OKLCH its lightness is 61%, its chroma 0.109 and its hue 238°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.022 away. Black text reads best on it, at 5.58:1.
| Hue family | Blues |
| Lightness | medium-dark (61%) |
| Chroma | moderately saturated (0.109) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.58:1 |
| White text | 3.76:1 |
Values
| HEX | #378BBC |
| RGB | rgb(55, 139, 188) |
| HSL | hsl(202, 55%, 48%) |
| OKLCH | oklch(60.8% 0.109 238.1) |
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 #378BBC | 3.76:1 | AA large text | Lc -70.4 | Content text, not long reading |
| Black text on #378BBC | 5.58:1 | AA | Lc 39.2 | Non-text elements, placeholder text |
| #378BBC text on white | 3.76:1 | AA large text | Lc 64.9 | Content text, not long reading |
| #378BBC text on black | 5.58:1 | AA | Lc -36.8 | 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
#F1F6FA
oklch(97.1% 0.008 241.7)
-
Step 100
100
#E1ECF3
oklch(93.7% 0.015 235.4)
-
Step 200
200
#C8DCEB
oklch(88.4% 0.03 240.2)
-
Step 300
300
#A1C6E0
oklch(80.8% 0.054 239)
-
Step 400
400
#6CA9D0
oklch(70.8% 0.085 237.7)
-
Step 500
500 (this color)
#378BBC
oklch(60.8% 0.109 238.1)
-
Step 600
600
#127CB0
oklch(55.7% 0.118 237.8)
-
Step 700
700
#006897
oklch(49.1% 0.109 238.1)
-
Step 800
800
#08557B
oklch(42.7% 0.092 238.2)
-
Step 900
900
#144663
oklch(37.6% 0.072 238.7)
-
Step 950
950
#0E293A
oklch(26.9% 0.046 239.3)
#378BBC 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) | #748BBE | 0.061 |
| Deuteranopia (no green cones) | #627EBB | 0.050 |
| Tritanopia (no blue cones) | #00979C | 0.072 |
| Achromatopsia (no color) | #848484 | 0.109 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #378BBC
#378BBC
oklch(60.8% 0.109 238.1)
- #B3713A
#B3713A
oklch(60.9% 0.109 58.3)
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 #378BBC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.022
- Blue NCS #118AB2 ΔE 0.025
- Steel Blue #4682B4 ΔE 0.026
- Off Blue #5684AE ΔE 0.033
- Water Blue #0E87CC ΔE 0.034
- Dusty Blue #5A86AD ΔE 0.035
- Faded Blue #658CBB ΔE 0.043
- Teal Blue #01889F ΔE 0.052
Use #378BBC 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.