#307DB5
Closest named color: Nice Blue (#107AB0). oklch(56.9% 0.114 244), rgb(48, 125, 181).
Aa
Black text reads best on this color (4.72:1).
About this color
#307DB5 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 57%, its chroma 0.114 and its hue 244°. Its hue sits on the cool side of the wheel. The nearest named color is Nice Blue (#107AB0), ΔE 0.020 away. Black text reads best on it, at 4.72:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.114) |
| Temperature | cool |
| Nearest name | Nice Blue (#107AB0) |
| Black text | 4.72:1 |
| White text | 4.44:1 |
Values
| HEX | #307DB5 |
| RGB | rgb(48, 125, 181) |
| HSL | hsl(205, 58%, 45%) |
| OKLCH | oklch(56.9% 0.114 244) |
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 #307DB5 | 4.44:1 | AA large text | Lc -76.0 | Fine for body text |
| Black text on #307DB5 | 4.72:1 | AA | Lc 33.6 | Non-text elements, placeholder text |
| #307DB5 text on white | 4.44:1 | AA large text | Lc 70.5 | Content text, not long reading |
| #307DB5 text on black | 4.72:1 | AA | Lc -31.2 | 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
#F2F6FA
oklch(97.1% 0.007 247.9)
-
Step 100
100
#E2EBF3
oklch(93.6% 0.015 244.7)
-
Step 200
200
#CADCEB
oklch(88.6% 0.028 243.1)
-
Step 300
300
#A5C5E0
oklch(80.9% 0.052 243.9)
-
Step 400
400
#73A7D1
oklch(70.8% 0.083 243.7)
-
Step 500
500
#4C90C4
oklch(63.1% 0.105 243.7)
-
Step 600
600 (this color)
#307DB5
oklch(56.9% 0.114 244)
-
Step 700
700
#1D6698
oklch(49.1% 0.106 243.7)
-
Step 800
800
#1B537B
oklch(42.6% 0.088 243.9)
-
Step 900
900
#1D4563
oklch(37.7% 0.068 243.8)
-
Step 950
950
#12293A
oklch(27.1% 0.043 242.6)
#307DB5 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) | #637FB7 | 0.051 |
| Deuteranopia (no green cones) | #5172B4 | 0.039 |
| Tritanopia (no blue cones) | #008B91 | 0.081 |
| Achromatopsia (no color) | #787878 | 0.114 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #307DB5
#307DB5
oklch(56.9% 0.114 244)
- #A56620
#A56620
oklch(56.8% 0.115 63.7)
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 #307DB5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Nice Blue #107AB0 ΔE 0.020
- Windows Blue #3778BF ΔE 0.024
- Steel Blue #4682B4 ΔE 0.025
- Flat Blue #3C73A8 ΔE 0.031
- Cool Blue #4984B8 ΔE 0.031
- Cerulean #457B9D ΔE 0.039
- Blue NCS #118AB2 ΔE 0.040
- Water Blue #0E87CC ΔE 0.040
Use #307DB5 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.