#247CCB
Closest named color: Windows Blue (#3778BF). oklch(57.6% 0.146 250.3), rgb(36, 124, 203).
Aa
Black text reads best on this color (4.82:1).
About this color
#247CCB is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.146 and its hue 250°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.021 away. Black text reads best on it, at 4.82:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.146) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.82:1 |
| White text | 4.35:1 |
Values
| HEX | #247CCB |
| RGB | rgb(36, 124, 203) |
| HSL | hsl(208, 70%, 47%) |
| OKLCH | oklch(57.6% 0.146 250.3) |
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 #247CCB | 4.35:1 | AA large text | Lc -75.2 | Fine for body text |
| Black text on #247CCB | 4.82:1 | AA | Lc 34.4 | Non-text elements, placeholder text |
| #247CCB text on white | 4.35:1 | AA large text | Lc 69.7 | Content text, not long reading |
| #247CCB text on black | 4.82:1 | AA | Lc -31.9 | 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
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E1EBF6
oklch(93.6% 0.018 250.6)
-
Step 200
200
#C8DCF1
oklch(88.6% 0.036 249.5)
-
Step 300
300
#A1C4EA
oklch(80.8% 0.066 250.7)
-
Step 400
400
#6DA5E0
oklch(70.7% 0.105 250.7)
-
Step 500
500
#428DD7
oklch(63% 0.134 250.5)
-
Step 600
600 (this color)
#247CCB
oklch(57.6% 0.146 250.3)
-
Step 700
700
#0A63AA
oklch(49.2% 0.136 250.2)
-
Step 800
800
#105189
oklch(42.7% 0.111 250.1)
-
Step 900
900
#17436E
oklch(37.6% 0.088 251)
-
Step 950
950
#0F2840
oklch(27% 0.055 249.7)
#247CCB 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) | #5681CE | 0.045 |
| Deuteranopia (no green cones) | #3B72C9 | 0.028 |
| Tritanopia (no blue cones) | #008F9A | 0.106 |
| Achromatopsia (no color) | #797979 | 0.146 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #247CCB
#247CCB
oklch(57.6% 0.146 250.3)
- #A76A00
#A76A00
oklch(57.7% 0.125 70.3)
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 #247CCB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.021
- Water Blue #0E87CC ΔE 0.030
- Nice Blue #107AB0 ΔE 0.044
- Steel Blue #4682B4 ΔE 0.049
- Cool Blue #4984B8 ΔE 0.050
- Flat Blue #3C73A8 ΔE 0.055
- Mid Blue #276AB3 ΔE 0.058
- French Blue #436BAD ΔE 0.060
Use #247CCB 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.