#2F51B5
Closest named color: Blue Blue (#2242C7). oklch(47% 0.164 266), rgb(47, 81, 181).
Aa
White text reads best on this color (7.08:1).
About this color
#2F51B5 is a medium-dark, vivid blue. In OKLCH its lightness is 47%, its chroma 0.164 and its hue 266°. Its hue sits on the cool side of the wheel. The nearest named color is Blue Blue (#2242C7), ΔE 0.048 away. White text reads best on it, at 7.08:1.
| Hue family | Blues |
| Lightness | medium-dark (47%) |
| Chroma | vivid (0.164) |
| Temperature | cool |
| Nearest name | Blue Blue (#2242C7) |
| Black text | 2.96:1 |
| White text | 7.08:1 |
Values
| HEX | #2F51B5 |
| RGB | rgb(47, 81, 181) |
| HSL | hsl(225, 59%, 45%) |
| OKLCH | oklch(47% 0.164 266) |
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 #2F51B5 | 7.08:1 | AAA | Lc -89.0 | Fine for body text |
| Black text on #2F51B5 | 2.96:1 | Fails | Lc 19.9 | Dividers and decoration only |
| #2F51B5 text on white | 7.08:1 | AAA | Lc 84.1 | Fine for body text |
| #2F51B5 text on black | 2.96:1 | Fails | Lc -17.9 | 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
#F2F5FD
oklch(97% 0.011 269.6)
-
Step 100
100
#E3EAFA
oklch(93.6% 0.023 266.9)
-
Step 200
200
#CCD9F7
oklch(88.5% 0.044 266.9)
-
Step 300
300
#A9C0F5
oklch(80.9% 0.079 266.4)
-
Step 400
400
#7B9EF0
oklch(70.8% 0.127 265.7)
-
Step 500
500
#5B83EA
oklch(63.1% 0.161 266)
-
Step 600
600
#426AD9
oklch(55.6% 0.176 265.9)
-
Step 700
700 (this color)
#2F51B5
oklch(47% 0.164 266)
-
Step 800
800
#2C4898
oklch(42.7% 0.135 266.2)
-
Step 900
900
#273D79
oklch(37.6% 0.106 266.3)
-
Step 950
950
#172447
oklch(26.9% 0.068 266.6)
#2F51B5 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) | #005FB8 | 0.039 |
| Deuteranopia (no green cones) | #0052B3 | 0.027 |
| Tritanopia (no blue cones) | #00697B | 0.129 |
| Achromatopsia (no color) | #585858 | 0.164 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2F51B5
#2F51B5
oklch(47% 0.164 266)
- #735600
#735600
oklch(47.1% 0.096 85.8)
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 #2F51B5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Blue Blue #2242C7 ΔE 0.048
- Majorelle Blue #3F37C9 ΔE 0.064
- Blueberry #464196 ΔE 0.065
- Blue With A Hint Of Purple #533CC6 ΔE 0.066
- Sapphire #2138AB ΔE 0.066
- Dusk Blue #26538D ΔE 0.067
- Mid Blue #276AB3 ΔE 0.067
- Denim Blue #3B5B92 ΔE 0.068
Use #2F51B5 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.