#1B73CF
Closest named color: Windows Blue (#3778BF). oklch(55.6% 0.163 254), rgb(27, 115, 207).
Aa
White text reads best on this color (4.77:1).
About this color
#1B73CF is a medium-dark, vivid blue. In OKLCH its lightness is 56%, its chroma 0.163 and its hue 254°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.035 away. White text reads best on it, at 4.77:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | vivid (0.163) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.39:1 |
| White text | 4.77:1 |
Values
| HEX | #1B73CF |
| RGB | rgb(27, 115, 207) |
| HSL | hsl(211, 77%, 46%) |
| OKLCH | oklch(55.6% 0.163 254) |
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 #1B73CF | 4.77:1 | AA | Lc -78.0 | Fine for body text |
| Black text on #1B73CF | 4.39:1 | AA large text | Lc 31.5 | Non-text elements, placeholder text |
| #1B73CF text on white | 4.77:1 | AA | Lc 72.6 | Content text, not long reading |
| #1B73CF text on black | 4.39:1 | AA large text | Lc -29.1 | Dividers and decoration only |
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
#E0EBF8
oklch(93.6% 0.021 252.5)
-
Step 200
200
#C7DBF4
oklch(88.4% 0.041 254)
-
Step 300
300
#A0C4F0
oklch(81% 0.074 253.7)
-
Step 400
400
#6BA4E8
oklch(70.8% 0.117 253.6)
-
Step 500
500
#418BE1
oklch(63.1% 0.149 254)
-
Step 600
600 (this color)
#1B73CF
oklch(55.6% 0.163 254)
-
Step 700
700
#0A60B3
oklch(49.1% 0.151 253.9)
-
Step 800
800
#0F4F91
oklch(42.8% 0.125 253.8)
-
Step 900
900
#164274
oklch(37.7% 0.098 254.2)
-
Step 950
950
#0E2744
oklch(27% 0.062 253.9)
#1B73CF 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) | #427BD3 | 0.037 |
| Deuteranopia (no green cones) | #186BCD | 0.022 |
| Tritanopia (no blue cones) | #008997 | 0.120 |
| Achromatopsia (no color) | #737373 | 0.163 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B73CF
#1B73CF
oklch(55.6% 0.163 254)
- #9C6700
#9C6700
oklch(55.7% 0.118 73.9)
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 #1B73CF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.035
- Royal Blue #4169E1 ΔE 0.046
- Mid Blue #276AB3 ΔE 0.046
- Cerulean Blue #056EEE ΔE 0.051
- Nice Blue #107AB0 ΔE 0.056
- Water Blue #0E87CC ΔE 0.056
- French Blue #436BAD ΔE 0.057
- Flat Blue #3C73A8 ΔE 0.063
Use #1B73CF 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.