#555BBC
Closest named color: Iris (#6258C4). oklch(51.7% 0.15 277.1), rgb(85, 91, 188).
Aa
White text reads best on this color (5.81:1).
About this color
#555BBC is a medium-dark, vivid blue. In OKLCH its lightness is 52%, its chroma 0.150 and its hue 277°. Its hue sits on the cool side of the wheel. The nearest named color is Iris (#6258C4), ΔE 0.024 away. White text reads best on it, at 5.81:1.
| Hue family | Blues |
| Lightness | medium-dark (52%) |
| Chroma | vivid (0.150) |
| Temperature | cool |
| Nearest name | Iris (#6258C4) |
| Black text | 3.60:1 |
| White text | 5.81:1 |
Values
| HEX | #555BBC |
| RGB | rgb(85, 91, 188) |
| HSL | hsl(237, 43%, 54%) |
| OKLCH | oklch(51.7% 0.15 277.1) |
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 #555BBC | 5.81:1 | AA | Lc -84.1 | Fine for body text |
| Black text on #555BBC | 3.60:1 | AA large text | Lc 25.2 | Dividers and decoration only |
| #555BBC text on white | 5.81:1 | AA | Lc 78.9 | Fine for body text |
| #555BBC text on black | 3.60:1 | AA large text | Lc -22.9 | 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
#F4F5FC
oklch(97.1% 0.009 279.7)
-
Step 100
100
#E6E9F8
oklch(93.6% 0.02 276.9)
-
Step 200
200
#D2D7F4
oklch(88.4% 0.04 277.8)
-
Step 300
300
#B4BDF0
oklch(80.9% 0.073 276.8)
-
Step 400
400
#8F99E8
oklch(70.7% 0.116 277.5)
-
Step 500
500
#747EE1
oklch(63.1% 0.148 276.9)
-
Step 600
600
#5E65CF
oklch(55.6% 0.161 277)
-
Step 700
700 (this color)
#555BBC
oklch(51.7% 0.15 277.1)
-
Step 800
800
#404591
oklch(42.8% 0.123 277)
-
Step 900
900
#363A74
oklch(37.6% 0.098 277.6)
-
Step 950
950
#1F2344
oklch(27.1% 0.061 276.3)
#555BBC 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) | #2869BF | 0.054 |
| Deuteranopia (no green cones) | #1761BA | 0.058 |
| Tritanopia (no blue cones) | #227183 | 0.131 |
| Achromatopsia (no color) | #656565 | 0.150 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #555BBC
#555BBC
oklch(51.7% 0.15 277.1)
- #796700
#796700
oklch(51.6% 0.106 97.1)
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 #555BBC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Iris #6258C4 ΔE 0.024
- Slate Blue #6A5ACD ΔE 0.041
- Dark Periwinkle #665FD1 ΔE 0.043
- Light Indigo #6D5ACF ΔE 0.047
- Warm Blue #4B57DB ΔE 0.052
- French Blue #436BAD ΔE 0.055
- Mid Blue #276AB3 ΔE 0.060
- Bluey Purple #6241C7 ΔE 0.063
Use #555BBC 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.