#2378E4
Closest named color: Cerulean Blue (#056EEE). oklch(58.3% 0.182 256.9), rgb(35, 120, 228).
Aa
Black text reads best on this color (4.87:1).
About this color
#2378E4 is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.182 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean Blue (#056EEE), ΔE 0.034 away. Black text reads best on it, at 4.87:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.182) |
| Temperature | cool |
| Nearest name | Cerulean Blue (#056EEE) |
| Black text | 4.87:1 |
| White text | 4.30:1 |
Values
| HEX | #2378E4 |
| RGB | rgb(35, 120, 228) |
| HSL | hsl(214, 78%, 52%) |
| OKLCH | oklch(58.3% 0.182 256.9) |
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 #2378E4 | 4.30:1 | AA large text | Lc -74.7 | Content text, not long reading |
| Black text on #2378E4 | 4.87:1 | AA | Lc 34.9 | Non-text elements, placeholder text |
| #2378E4 text on white | 4.30:1 | AA large text | Lc 69.2 | Content text, not long reading |
| #2378E4 text on black | 4.87:1 | AA | Lc -32.5 | 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 600.
-
Step 50
50
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E0EBFA
oklch(93.6% 0.024 256.1)
-
Step 200
200
#C6DBF8
oklch(88.5% 0.046 256.5)
-
Step 300
300
#9FC3F6
oklch(80.9% 0.082 257.1)
-
Step 400
400
#69A2F1
oklch(70.7% 0.131 256.8)
-
Step 500
500
#3E88EC
oklch(63% 0.168 256.9)
-
Step 600
600 (this color)
#2378E4
oklch(58.3% 0.182 256.9)
-
Step 700
700
#065DBE
oklch(49.2% 0.169 256.7)
-
Step 800
800
#0D4C99
oklch(42.6% 0.14 256.9)
-
Step 900
900
#14407A
oklch(37.6% 0.11 256.9)
-
Step 950
950
#0E2647
oklch(27% 0.068 257.1)
#2378E4 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) | #3983E8 | 0.035 |
| Deuteranopia (no green cones) | #0072E2 | 0.021 |
| Tritanopia (no blue cones) | #0092A3 | 0.138 |
| Achromatopsia (no color) | #7A7A7A | 0.182 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2378E4
#2378E4
oklch(58.3% 0.182 256.9)
- #A37000
#A37000
oklch(58.3% 0.122 77.2)
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 #2378E4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean Blue #056EEE ΔE 0.034
- Clear Blue #247AFD ΔE 0.038
- Royal Blue #4169E1 ΔE 0.039
- Windows Blue #3778BF ΔE 0.057
- Water Blue #0E87CC ΔE 0.059
- Neon Blue #4361EE ΔE 0.059
- Bright Blue #0165FC ΔE 0.063
- Dark Sky Blue #448EE4 ΔE 0.067
Use #2378E4 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.