#304399
Closest named color: Cobalt (#1E488F). oklch(41.9% 0.142 269.8), rgb(48, 67, 153).
Aa
White text reads best on this color (8.79:1).
About this color
#304399 is a dark, vivid blue. In OKLCH its lightness is 42%, its chroma 0.142 and its hue 270°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.028 away. White text reads best on it, at 8.79:1.
| Hue family | Blues |
| Lightness | dark (42%) |
| Chroma | vivid (0.142) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.38:1 |
| White text | 8.79:1 |
Values
| HEX | #304399 |
| RGB | rgb(48, 67, 153) |
| HSL | hsl(229, 52%, 39%) |
| OKLCH | oklch(41.9% 0.142 269.8) |
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 #304399 | 8.79:1 | AAA | Lc -94.2 | Preferred for body text |
| Black text on #304399 | 2.38:1 | Fails | Lc 14.3 | Not readable |
| #304399 text on white | 8.79:1 | AAA | Lc 89.7 | Fine for body text |
| #304399 text on black | 2.38:1 | Fails | Lc -12.5 | Not readable |
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 800.
-
Step 50
50
#F2F5FD
oklch(97% 0.011 269.6)
-
Step 100
100
#E3EAFB
oklch(93.7% 0.024 267.9)
-
Step 200
200
#CDD8F9
oklch(88.4% 0.047 270.8)
-
Step 300
300
#ABBFF7
oklch(80.9% 0.083 269.3)
-
Step 400
400
#809BF3
oklch(70.6% 0.133 269.8)
-
Step 500
500
#6280EF
oklch(63.2% 0.169 269.7)
-
Step 600
600
#4B66DD
oklch(55.6% 0.184 269.8)
-
Step 700
700
#3D54C0
oklch(49.2% 0.171 269.9)
-
Step 800
800 (this color)
#304399
oklch(41.9% 0.142 269.8)
-
Step 900
900
#2B3B7C
oklch(37.7% 0.112 269.9)
-
Step 950
950
#192348
oklch(26.9% 0.07 269.8)
#304399 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) | #004F9C | 0.040 |
| Deuteranopia (no green cones) | #004697 | 0.034 |
| Tritanopia (no blue cones) | #005867 | 0.117 |
| Achromatopsia (no color) | #4B4B4B | 0.142 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #304399
#304399
oklch(41.9% 0.142 269.8)
- #5F4A00
#5F4A00
oklch(41.9% 0.086 90)
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 #304399, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.028
- Blueberry #464196 ΔE 0.031
- Dark Slate Blue #483D8B ΔE 0.042
- Sapphire #2138AB ΔE 0.044
- Dusk Blue #26538D ΔE 0.050
- Light Navy #155084 ΔE 0.057
- Twilight Blue #0A437A ΔE 0.063
- Twilight #4E518B ΔE 0.066
Use #304399 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.