#307CB4
Closest named color: Nice Blue (#107AB0). oklch(56.6% 0.114 244.3), rgb(48, 124, 180).
Aa
Black text reads best on this color (4.66:1).
About this color
#307CB4 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 0.019 away. Black text reads best on it, at 4.66:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.114) |
| Temperature | cool |
| Nearest name | Nice Blue (#107AB0) |
| Black text | 4.66:1 |
| White text | 4.49:1 |
Values
| HEX | #307CB4 |
| RGB | rgb(48, 124, 180) |
| HSL | hsl(205, 58%, 45%) |
| OKLCH | oklch(56.6% 0.114 244.3) |
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 #307CB4 | 4.49:1 | AA large text | Lc -76.4 | Fine for body text |
| Black text on #307CB4 | 4.66:1 | AA | Lc 33.2 | Non-text elements, placeholder text |
| #307CB4 text on white | 4.49:1 | AA large text | Lc 70.9 | Content text, not long reading |
| #307CB4 text on black | 4.66:1 | AA | Lc -30.8 | 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
#74A6D0
oklch(70.6% 0.082 244.7)
-
Step 500
500
#4D90C4
oklch(63.1% 0.104 244)
-
Step 600
600 (this color)
#307CB4
oklch(56.6% 0.114 244.3)
-
Step 700
700
#1E6698
oklch(49.2% 0.106 243.9)
-
Step 800
800
#1C537B
oklch(42.6% 0.087 244.2)
-
Step 900
900
#1E4563
oklch(37.7% 0.068 244.3)
-
Step 950
950
#12293A
oklch(27.1% 0.043 242.6)
#307CB4 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) | #627EB6 | 0.050 |
| Deuteranopia (no green cones) | #5071B3 | 0.039 |
| Tritanopia (no blue cones) | #008A90 | 0.082 |
| Achromatopsia (no color) | #777777 | 0.114 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #307CB4
#307CB4
oklch(56.6% 0.114 244.3)
- #A4661F
#A4661F
oklch(56.6% 0.114 64.4)
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 #307CB4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Nice Blue #107AB0 ΔE 0.019
- Windows Blue #3778BF ΔE 0.023
- Steel Blue #4682B4 ΔE 0.027
- Flat Blue #3C73A8 ΔE 0.028
- Cool Blue #4984B8 ΔE 0.033
- Cerulean #457B9D ΔE 0.038
- Muted Blue #3B719F ΔE 0.040
- Dull Blue #49759C ΔE 0.040
Use #307CB4 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.