#155BBB
Closest named color: Mid Blue (#276AB3). oklch(48.8% 0.166 258.3), rgb(21, 91, 187).
Aa
White text reads best on this color (6.46:1).
About this color
#155BBB is a medium-dark, vivid blue. In OKLCH its lightness is 49%, its chroma 0.166 and its hue 258°. Its hue sits on the cool side of the wheel. The nearest named color is Mid Blue (#276AB3), ΔE 0.048 away. White text reads best on it, at 6.46:1.
| Hue family | Blues |
| Lightness | medium-dark (49%) |
| Chroma | vivid (0.166) |
| Temperature | cool |
| Nearest name | Mid Blue (#276AB3) |
| Black text | 3.24:1 |
| White text | 6.46:1 |
Values
| HEX | #155BBB |
| RGB | rgb(21, 91, 187) |
| HSL | hsl(215, 80%, 41%) |
| OKLCH | oklch(48.8% 0.166 258.3) |
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 #155BBB | 6.46:1 | AA | Lc -86.6 | Fine for body text |
| Black text on #155BBB | 3.24:1 | AA large text | Lc 22.6 | Dividers and decoration only |
| #155BBB text on white | 6.46:1 | AA | Lc 81.5 | Fine for body text |
| #155BBB text on black | 3.24:1 | AA large text | Lc -20.4 | 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
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E1EBFA
oklch(93.7% 0.023 258.4)
-
Step 200
200
#C7DBF7
oklch(88.5% 0.044 256.8)
-
Step 300
300
#A1C3F5
oklch(81% 0.08 257.9)
-
Step 400
400
#6DA1F0
oklch(70.6% 0.129 258.5)
-
Step 500
500
#4588EB
oklch(63.2% 0.164 258.2)
-
Step 600
600
#246FD9
oklch(55.6% 0.178 258.2)
-
Step 700
700 (this color)
#155BBB
oklch(48.8% 0.166 258.3)
-
Step 800
800
#164C98
oklch(42.8% 0.137 258.2)
-
Step 900
900
#194079
oklch(37.7% 0.107 258.2)
-
Step 950
950
#102647
oklch(27% 0.068 258.4)
#155BBB 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) | #1966BE | 0.030 |
| Deuteranopia (no green cones) | #0057B9 | 0.014 |
| Tritanopia (no blue cones) | #007382 | 0.127 |
| Achromatopsia (no color) | #5E5E5E | 0.166 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #155BBB
#155BBB
oklch(48.8% 0.166 258.3)
- #7F5700
#7F5700
oklch(48.8% 0.102 77.8)
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 #155BBB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Mid Blue #276AB3 ΔE 0.048
- Blue Blue #2242C7 ΔE 0.062
- French Blue #436BAD ΔE 0.067
- Denim Blue #3B5B92 ΔE 0.070
- Warm Blue #4B57DB ΔE 0.070
- Dusk Blue #26538D ΔE 0.074
- Peacock Blue #016795 ΔE 0.075
- Azul #1D5DEC ΔE 0.077
Use #155BBB 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.