#1F77BF
Closest named color: Windows Blue (#3778BF). oklch(55.6% 0.137 248.6), rgb(31, 119, 191).
Aa
White text reads best on this color (4.71:1).
About this color
#1F77BF is a medium-dark, moderately saturated blue. In OKLCH its lightness is 56%, its chroma 0.137 and its hue 249°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.016 away. White text reads best on it, at 4.71:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.137) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.44:1 |
| White text | 4.71:1 |
Values
| HEX | #1F77BF |
| RGB | rgb(31, 119, 191) |
| HSL | hsl(207, 72%, 44%) |
| OKLCH | oklch(55.6% 0.137 248.6) |
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 #1F77BF | 4.71:1 | AA | Lc -77.8 | Fine for body text |
| Black text on #1F77BF | 4.44:1 | AA large text | Lc 31.8 | Non-text elements, placeholder text |
| #1F77BF text on white | 4.71:1 | AA | Lc 72.3 | Content text, not long reading |
| #1F77BF text on black | 4.44:1 | AA large text | Lc -29.4 | 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
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E1EBF6
oklch(93.6% 0.018 250.6)
-
Step 200
200
#C8DCEF
oklch(88.5% 0.034 246.8)
-
Step 300
300
#A2C5E7
oklch(80.9% 0.061 247.8)
-
Step 400
400
#6EA6DC
oklch(70.8% 0.099 248.5)
-
Step 500
500
#448ED2
oklch(63% 0.127 248.8)
-
Step 600
600 (this color)
#1F77BF
oklch(55.6% 0.137 248.6)
-
Step 700
700
#0F64A5
oklch(49.2% 0.127 248.5)
-
Step 800
800
#125286
oklch(42.8% 0.106 248.5)
-
Step 900
900
#18446B
oklch(37.7% 0.082 248.7)
-
Step 950
950
#10283F
oklch(27% 0.053 249.5)
#1F77BF 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) | #547BC2 | 0.046 |
| Deuteranopia (no green cones) | #3C6DBE | 0.031 |
| Tritanopia (no blue cones) | #008892 | 0.098 |
| Achromatopsia (no color) | #737373 | 0.137 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1F77BF
#1F77BF
oklch(55.6% 0.137 248.6)
- #A16400
#A16400
oklch(55.7% 0.122 68.7)
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 #1F77BF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.016
- Nice Blue #107AB0 ΔE 0.028
- Mid Blue #276AB3 ΔE 0.038
- Flat Blue #3C73A8 ΔE 0.038
- French Blue #436BAD ΔE 0.043
- Water Blue #0E87CC ΔE 0.045
- Steel Blue #4682B4 ΔE 0.050
- Muted Blue #3B719F ΔE 0.050
Use #1F77BF 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.