#1B78CD
Closest named color: Windows Blue (#3778BF). oklch(56.6% 0.154 251.5), rgb(27, 120, 205).
Aa
Black text reads best on this color (4.61:1).
About this color
#1B78CD is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.154 and its hue 252°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.026 away. Black text reads best on it, at 4.61:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.154) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.61:1 |
| White text | 4.55:1 |
Values
| HEX | #1B78CD |
| RGB | rgb(27, 120, 205) |
| HSL | hsl(209, 77%, 45%) |
| OKLCH | oklch(56.6% 0.154 251.5) |
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 #1B78CD | 4.55:1 | AA | Lc -76.5 | Fine for body text |
| Black text on #1B78CD | 4.61:1 | AA | Lc 33.0 | Non-text elements, placeholder text |
| #1B78CD text on white | 4.55:1 | AA | Lc 71.1 | Content text, not long reading |
| #1B78CD text on black | 4.61:1 | AA | Lc -30.6 | 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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E0EBF7
oklch(93.5% 0.02 250.4)
-
Step 200
200
#C7DBF3
oklch(88.4% 0.04 253)
-
Step 300
300
#A0C4ED
oklch(80.8% 0.07 252)
-
Step 400
400
#6BA5E4
oklch(70.8% 0.111 251.5)
-
Step 500
500
#3F8DDC
oklch(63.2% 0.142 251.3)
-
Step 600
600 (this color)
#1B78CD
oklch(56.6% 0.154 251.5)
-
Step 700
700
#0362AE
oklch(49.2% 0.143 251.3)
-
Step 800
800
#0B508D
oklch(42.7% 0.119 251.5)
-
Step 900
900
#154371
oklch(37.7% 0.093 251.7)
-
Step 950
950
#0E2842
oklch(27.1% 0.058 250.8)
#1B78CD 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) | #4D7ED0 | 0.042 |
| Deuteranopia (no green cones) | #2D6FCB | 0.024 |
| Tritanopia (no blue cones) | #008C98 | 0.113 |
| Achromatopsia (no color) | #767676 | 0.154 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B78CD
#1B78CD
oklch(56.6% 0.154 251.5)
- #A26800
#A26800
oklch(56.6% 0.122 71.4)
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 #1B78CD, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.026
- Water Blue #0E87CC ΔE 0.042
- Nice Blue #107AB0 ΔE 0.048
- Mid Blue #276AB3 ΔE 0.051
- Royal Blue #4169E1 ΔE 0.056
- French Blue #436BAD ΔE 0.058
- Flat Blue #3C73A8 ΔE 0.058
- Cerulean Blue #056EEE ΔE 0.060
Use #1B78CD 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.