#107DCB
Closest named color: Windows Blue (#3778BF). oklch(57.5% 0.149 247.7), rgb(16, 125, 203).
Aa
Black text reads best on this color (4.81:1).
About this color
#107DCB is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.149 and its hue 248°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.025 away. Black text reads best on it, at 4.81:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.149) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.81:1 |
| White text | 4.35:1 |
Values
| HEX | #107DCB |
| RGB | rgb(16, 125, 203) |
| HSL | hsl(205, 85%, 43%) |
| OKLCH | oklch(57.5% 0.149 247.7) |
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 #107DCB | 4.35:1 | AA large text | Lc -75.1 | Fine for body text |
| Black text on #107DCB | 4.81:1 | AA | Lc 34.5 | Non-text elements, placeholder text |
| #107DCB text on white | 4.35:1 | AA large text | Lc 69.6 | Content text, not long reading |
| #107DCB text on black | 4.81:1 | AA | Lc -32.1 | 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
#E0EBF6
oklch(93.5% 0.019 248)
-
Step 200
200
#C6DCF1
oklch(88.5% 0.037 247)
-
Step 300
300
#9FC5EA
oklch(80.9% 0.066 248)
-
Step 400
400
#68A6E0
oklch(70.7% 0.107 248)
-
Step 500
500
#398FD7
oklch(63.2% 0.136 247.4)
-
Step 600
600 (this color)
#107DCB
oklch(57.5% 0.149 247.7)
-
Step 700
700
#0064A6
oklch(49.1% 0.131 247.6)
-
Step 800
800
#00528A
oklch(42.8% 0.115 247.8)
-
Step 900
900
#10446E
oklch(37.6% 0.089 247.9)
-
Step 950
950
#0C2840
oklch(26.9% 0.056 247.6)
#107DCB 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) | #5781CE | 0.052 |
| Deuteranopia (no green cones) | #3A72CA | 0.033 |
| Tritanopia (no blue cones) | #00909A | 0.106 |
| Achromatopsia (no color) | #797979 | 0.149 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #107DCB
#107DCB
oklch(57.5% 0.149 247.7)
- #A96800
#A96800
oklch(57.5% 0.126 67.8)
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 #107DCB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.025
- Water Blue #0E87CC ΔE 0.028
- Nice Blue #107AB0 ΔE 0.042
- Steel Blue #4682B4 ΔE 0.051
- Cool Blue #4984B8 ΔE 0.052
- Flat Blue #3C73A8 ΔE 0.057
- Mid Blue #276AB3 ΔE 0.058
- Blue NCS #118AB2 ΔE 0.060
Use #107DCB 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.