#366EA1
Closest named color: Muted Blue (#3B719F). oklch(52.4% 0.1 248.3), rgb(54, 110, 161).
Aa
White text reads best on this color (5.38:1).
About this color
#366EA1 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 52%, its chroma 0.100 and its hue 248°. Its hue sits on the cool side of the wheel. The nearest named color is Muted Blue (#3B719F), ΔE 0.012 away. White text reads best on it, at 5.38:1.
| Hue family | Blues |
| Lightness | medium-dark (52%) |
| Chroma | moderately saturated (0.100) |
| Temperature | cool |
| Nearest name | Muted Blue (#3B719F) |
| Black text | 3.90:1 |
| White text | 5.38:1 |
Values
| HEX | #366EA1 |
| RGB | rgb(54, 110, 161) |
| HSL | hsl(209, 50%, 42%) |
| OKLCH | oklch(52.4% 0.1 248.3) |
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 #366EA1 | 5.38:1 | AA | Lc -81.9 | Fine for body text |
| Black text on #366EA1 | 3.90:1 | AA large text | Lc 27.5 | Dividers and decoration only |
| #366EA1 text on white | 5.38:1 | AA | Lc 76.6 | Fine for body text |
| #366EA1 text on black | 3.90:1 | AA large text | Lc -25.2 | Dividers and decoration only |
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
#F2F6F9
oklch(97.1% 0.006 239.8)
-
Step 100
100
#E3EBF2
oklch(93.6% 0.013 244.3)
-
Step 200
200
#CDDBE9
oklch(88.5% 0.025 248.1)
-
Step 300
300
#ABC4DD
oklch(81% 0.045 248.4)
-
Step 400
400
#7DA5CC
oklch(70.7% 0.072 248.2)
-
Step 500
500
#5B8EBF
oklch(63.1% 0.092 248.5)
-
Step 600
600 (this color)
#366EA1
oklch(52.4% 0.1 248.3)
-
Step 700
700
#316493
oklch(49% 0.094 248.6)
-
Step 800
800
#2A5277
oklch(42.7% 0.077 248.4)
-
Step 900
900
#264460
oklch(37.7% 0.06 248.1)
-
Step 950
950
#172838
oklch(27% 0.038 247.9)
#366EA1 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) | #5870A3 | 0.038 |
| Deuteranopia (no green cones) | #4966A0 | 0.027 |
| Tritanopia (no blue cones) | #007A80 | 0.077 |
| Achromatopsia (no color) | #6A6A6A | 0.100 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #366EA1
#366EA1
oklch(52.4% 0.1 248.3)
- #8F5E1E
#8F5E1E
oklch(52.4% 0.1 68.9)
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 #366EA1, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Muted Blue #3B719F ΔE 0.012
- Flat Blue #3C73A8 ΔE 0.018
- French Blue #436BAD ΔE 0.026
- Ocean Blue #03719C ΔE 0.028
- Dull Blue #49759C ΔE 0.032
- Mid Blue #276AB3 ΔE 0.035
- Sea Blue #047495 ΔE 0.038
- Nice Blue #107AB0 ΔE 0.038
Use #366EA1 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.