#3665BB
Closest named color: Mid Blue (#276AB3). oklch(52% 0.145 261.3), rgb(54, 101, 187).
Aa
White text reads best on this color (5.62:1).
About this color
#3665BB is a medium-dark, vivid blue. In OKLCH its lightness is 52%, its chroma 0.145 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Mid Blue (#276AB3), ΔE 0.022 away. White text reads best on it, at 5.62:1.
| Hue family | Blues |
| Lightness | medium-dark (52%) |
| Chroma | vivid (0.145) |
| Temperature | cool |
| Nearest name | Mid Blue (#276AB3) |
| Black text | 3.73:1 |
| White text | 5.62:1 |
Values
| HEX | #3665BB |
| RGB | rgb(54, 101, 187) |
| HSL | hsl(219, 55%, 47%) |
| OKLCH | oklch(52% 0.145 261.3) |
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 #3665BB | 5.62:1 | AA | Lc -83.1 | Fine for body text |
| Black text on #3665BB | 3.73:1 | AA large text | Lc 26.3 | Dividers and decoration only |
| #3665BB text on white | 5.62:1 | AA | Lc 77.8 | Fine for body text |
| #3665BB text on black | 3.73:1 | AA large text | Lc -24.0 | 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 700.
-
Step 50
50
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E2EAF8
oklch(93.5% 0.021 261.8)
-
Step 200
200
#CBDAF4
oklch(88.5% 0.039 261.5)
-
Step 300
300
#A8C2EF
oklch(81% 0.07 261.3)
-
Step 400
400
#79A1E7
oklch(70.8% 0.112 261.2)
-
Step 500
500
#5687DF
oklch(63% 0.143 261.2)
-
Step 600
600
#3C6FCD
oklch(55.6% 0.156 261.4)
-
Step 700
700 (this color)
#3665BB
oklch(52% 0.145 261.3)
-
Step 800
800
#274C90
oklch(42.7% 0.12 261.4)
-
Step 900
900
#244073
oklch(37.8% 0.094 261.4)
-
Step 950
950
#152643
oklch(27% 0.059 260.5)
#3665BB 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) | #396EBE | 0.025 |
| Deuteranopia (no green cones) | #1D62B9 | 0.022 |
| Tritanopia (no blue cones) | #007987 | 0.115 |
| Achromatopsia (no color) | #676767 | 0.145 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3665BB
#3665BB
oklch(52% 0.145 261.3)
- #886100
#886100
oklch(52% 0.107 81.1)
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 #3665BB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Mid Blue #276AB3 ΔE 0.022
- French Blue #436BAD ΔE 0.033
- Windows Blue #3778BF ΔE 0.052
- Flat Blue #3C73A8 ΔE 0.055
- Royal Blue #4169E1 ΔE 0.061
- Muted Blue #3B719F ΔE 0.062
- Iris #6258C4 ΔE 0.062
- Dusky Blue #475F94 ΔE 0.062
Use #3665BB 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.