#1173CC
Closest named color: Windows Blue (#3778BF). oklch(55.3% 0.16 252.4), rgb(17, 115, 204).
Aa
White text reads best on this color (4.82:1).
About this color
#1173CC is a medium-dark, vivid blue. In OKLCH its lightness is 55%, its chroma 0.160 and its hue 252°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.034 away. White text reads best on it, at 4.82:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | vivid (0.160) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.34:1 |
| White text | 4.82:1 |
Values
| HEX | #1173CC |
| RGB | rgb(17, 115, 204) |
| HSL | hsl(209, 85%, 43%) |
| OKLCH | oklch(55.3% 0.16 252.4) |
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 #1173CC | 4.82:1 | AA | Lc -78.3 | Fine for body text |
| Black text on #1173CC | 4.34:1 | AA large text | Lc 31.2 | Non-text elements, placeholder text |
| #1173CC text on white | 4.82:1 | AA | Lc 72.9 | Content text, not long reading |
| #1173CC text on black | 4.34:1 | AA large text | Lc -28.8 | 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
#9FC4EF
oklch(80.9% 0.073 252.5)
-
Step 400
400
#6AA4E7
oklch(70.7% 0.116 252.9)
-
Step 500
500
#3D8CDF
oklch(63.1% 0.147 252.2)
-
Step 600
600 (this color)
#1173CC
oklch(55.3% 0.16 252.4)
-
Step 700
700
#0061B1
oklch(49.1% 0.148 252.3)
-
Step 800
800
#094F90
oklch(42.6% 0.124 252.7)
-
Step 900
900
#144373
oklch(37.8% 0.096 252.3)
-
Step 950
950
#0D2743
oklch(26.9% 0.061 252.5)
#1173CC 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) | #447ACF | 0.040 |
| Deuteranopia (no green cones) | #1D6ACA | 0.024 |
| Tritanopia (no blue cones) | #008995 | 0.120 |
| Achromatopsia (no color) | #727272 | 0.160 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1173CC
#1173CC
oklch(55.3% 0.16 252.4)
- #9C6500
#9C6500
oklch(55.3% 0.118 72.2)
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 #1173CC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.034
- Mid Blue #276AB3 ΔE 0.042
- Royal Blue #4169E1 ΔE 0.051
- Nice Blue #107AB0 ΔE 0.052
- French Blue #436BAD ΔE 0.055
- Cerulean Blue #056EEE ΔE 0.055
- Water Blue #0E87CC ΔE 0.056
- Flat Blue #3C73A8 ΔE 0.060
Use #1173CC 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.