#555DBB
Closest named color: Iris (#6258C4). oklch(52% 0.146 276.4), rgb(85, 93, 187).
Aa
White text reads best on this color (5.72:1).
About this color
#555DBB is a medium-dark, vivid blue. In OKLCH its lightness is 52%, its chroma 0.146 and its hue 276°. Its hue sits on the cool side of the wheel. The nearest named color is Iris (#6258C4), ΔE 0.026 away. White text reads best on it, at 5.72:1.
| Hue family | Blues |
| Lightness | medium-dark (52%) |
| Chroma | vivid (0.146) |
| Temperature | cool |
| Nearest name | Iris (#6258C4) |
| Black text | 3.66:1 |
| White text | 5.72:1 |
Values
| HEX | #555DBB |
| RGB | rgb(85, 93, 187) |
| HSL | hsl(235, 43%, 53%) |
| OKLCH | oklch(52% 0.146 276.4) |
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 #555DBB | 5.72:1 | AA | Lc -83.7 | Fine for body text |
| Black text on #555DBB | 3.66:1 | AA large text | Lc 25.7 | Dividers and decoration only |
| #555DBB text on white | 5.72:1 | AA | Lc 78.4 | Fine for body text |
| #555DBB text on black | 3.66:1 | AA large text | Lc -23.4 | 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
#F3F5FC
oklch(97.1% 0.01 273.4)
-
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
#B4BDEF
oklch(80.9% 0.071 276.7)
-
Step 400
400
#8E9AE6
oklch(70.7% 0.112 276.3)
-
Step 500
500
#747FDF
oklch(63.1% 0.144 276.5)
-
Step 600
600
#5D66CD
oklch(55.6% 0.157 276.3)
-
Step 700
700 (this color)
#555DBB
oklch(52% 0.146 276.4)
-
Step 800
800
#3F4590
oklch(42.6% 0.122 276.5)
-
Step 900
900
#353B73
oklch(37.7% 0.095 276.2)
-
Step 950
950
#1F2343
oklch(27% 0.059 276.3)
#555DBB 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) | #2E6BBE | 0.050 |
| Deuteranopia (no green cones) | #2062B9 | 0.053 |
| Tritanopia (no blue cones) | #237283 | 0.128 |
| Achromatopsia (no color) | #666666 | 0.146 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #555DBB
#555DBB
oklch(52% 0.146 276.4)
- #7B6800
#7B6800
oklch(52% 0.107 96.5)
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 #555DBB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Iris #6258C4 ΔE 0.026
- Slate Blue #6A5ACD ΔE 0.043
- Dark Periwinkle #665FD1 ΔE 0.043
- Light Indigo #6D5ACF ΔE 0.048
- French Blue #436BAD ΔE 0.050
- Warm Blue #4B57DB ΔE 0.055
- Mid Blue #276AB3 ΔE 0.057
- Royal Blue #4169E1 ΔE 0.065
Use #555DBB 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.