#3748BD
Closest named color: Blue Blue (#2242C7). oklch(46.3% 0.183 271), rgb(55, 72, 189).
Aa
White text reads best on this color (7.43:1).
About this color
#3748BD is a medium-dark, vivid blue. In OKLCH its lightness is 46%, its chroma 0.183 and its hue 271°. Its hue sits on the cool side of the wheel. The nearest named color is Blue Blue (#2242C7), ΔE 0.031 away. White text reads best on it, at 7.43:1.
| Hue family | Blues |
| Lightness | medium-dark (46%) |
| Chroma | vivid (0.183) |
| Temperature | cool |
| Nearest name | Blue Blue (#2242C7) |
| Black text | 2.82:1 |
| White text | 7.43:1 |
Values
| HEX | #3748BD |
| RGB | rgb(55, 72, 189) |
| HSL | hsl(232, 55%, 48%) |
| OKLCH | oklch(46.3% 0.183 271) |
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 #3748BD | 7.43:1 | AAA | Lc -90.1 | Preferred for body text |
| Black text on #3748BD | 2.82:1 | Fails | Lc 18.7 | Dividers and decoration only |
| #3748BD text on white | 7.43:1 | AAA | Lc 85.3 | Fine for body text |
| #3748BD text on black | 2.82:1 | Fails | Lc -16.7 | 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
#F2F5FE
oklch(97% 0.012 271.3)
-
Step 100
100
#E3E9FC
oklch(93.5% 0.027 271.9)
-
Step 200
200
#CDD8FB
oklch(88.5% 0.05 271.6)
-
Step 300
300
#ABBEFB
oklch(80.9% 0.089 270.9)
-
Step 400
400
#809AF9
oklch(70.7% 0.142 270.8)
-
Step 500
500
#637DF5
oklch(63% 0.181 271.2)
-
Step 600
600
#4C63E4
oklch(55.6% 0.196 270.9)
-
Step 700
700 (this color)
#3748BD
oklch(46.3% 0.183 271)
-
Step 800
800
#3343A0
oklch(42.7% 0.151 271.1)
-
Step 900
900
#2C3A7F
oklch(37.7% 0.117 271.1)
-
Step 950
950
#19224B
oklch(26.9% 0.077 271.1)
#3748BD 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) | #005CC1 | 0.053 |
| Deuteranopia (no green cones) | #004FBB | 0.037 |
| Tritanopia (no blue cones) | #00667B | 0.148 |
| Achromatopsia (no color) | #555555 | 0.184 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3748BD
#3748BD
oklch(46.3% 0.183 271)
- #6D5600
#6D5600
oklch(46.3% 0.095 90.7)
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 #3748BD, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Blue Blue #2242C7 ΔE 0.031
- Majorelle Blue #3F37C9 ΔE 0.038
- Blue With A Hint Of Purple #533CC6 ΔE 0.045
- Blurple #5539CC ΔE 0.053
- Sapphire #2138AB ΔE 0.057
- Bluey Purple #6241C7 ΔE 0.066
- Warm Blue #4B57DB ΔE 0.066
- Blueberry #464196 ΔE 0.066
Use #3748BD 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.