#1C78DD
Closest named color: Cerulean Blue (#056EEE). oklch(57.7% 0.175 255), rgb(28, 120, 221).
Aa
Black text reads best on this color (4.78:1).
About this color
#1C78DD is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.175 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean Blue (#056EEE), ΔE 0.039 away. Black text reads best on it, at 4.78:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.175) |
| Temperature | cool |
| Nearest name | Cerulean Blue (#056EEE) |
| Black text | 4.78:1 |
| White text | 4.39:1 |
Values
| HEX | #1C78DD |
| RGB | rgb(28, 120, 221) |
| HSL | hsl(211, 78%, 49%) |
| OKLCH | oklch(57.7% 0.175 255) |
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 #1C78DD | 4.39:1 | AA large text | Lc -75.3 | Fine for body text |
| Black text on #1C78DD | 4.78:1 | AA | Lc 34.2 | Non-text elements, placeholder text |
| #1C78DD text on white | 4.39:1 | AA large text | Lc 69.9 | Content text, not long reading |
| #1C78DD text on black | 4.78:1 | AA | Lc -31.8 | 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 600.
-
Step 50
50
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E0EBF9
oklch(93.6% 0.022 254.4)
-
Step 200
200
#C6DBF6
oklch(88.4% 0.044 254.8)
-
Step 300
300
#9FC4F3
oklch(81% 0.078 254.6)
-
Step 400
400
#68A3ED
oklch(70.6% 0.125 254.8)
-
Step 500
500
#3C8AE8
oklch(63.1% 0.161 255)
-
Step 600
600 (this color)
#1C78DD
oklch(57.7% 0.175 255)
-
Step 700
700
#005EB9
oklch(49% 0.162 255.1)
-
Step 800
800
#084E96
oklch(42.8% 0.134 254.8)
-
Step 900
900
#134177
oklch(37.6% 0.104 255.1)
-
Step 950
950
#0D2746
oklch(27.1% 0.066 254.6)
#1C78DD 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) | #4081E1 | 0.036 |
| Deuteranopia (no green cones) | #0471DB | 0.021 |
| Tritanopia (no blue cones) | #0090A0 | 0.129 |
| Achromatopsia (no color) | #787878 | 0.175 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1C78DD
#1C78DD
oklch(57.7% 0.175 255)
- #A36D00
#A36D00
oklch(57.7% 0.122 74.8)
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 #1C78DD, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean Blue #056EEE ΔE 0.039
- Royal Blue #4169E1 ΔE 0.042
- Windows Blue #3778BF ΔE 0.048
- Clear Blue #247AFD ΔE 0.049
- Water Blue #0E87CC ΔE 0.052
- Neon Blue #4361EE ΔE 0.065
- Dark Sky Blue #448EE4 ΔE 0.069
- Bright Blue #0165FC ΔE 0.069
Use #1C78DD 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.