#6599BC
Closest named color: Greyblue (#77A1B5). oklch(66% 0.076 238.9), rgb(101, 153, 188).
Aa
Black text reads best on this color (6.83:1).
About this color
#6599BC is a medium-light, moderately saturated blue. In OKLCH its lightness is 66%, its chroma 0.076 and its hue 239°. Its hue sits on the cool side of the wheel. The nearest named color is Greyblue (#77A1B5), ΔE 0.036 away. Black text reads best on it, at 6.83:1.
| Hue family | Blues |
| Lightness | medium-light (66%) |
| Chroma | moderately saturated (0.076) |
| Temperature | cool |
| Nearest name | Greyblue (#77A1B5) |
| Black text | 6.83:1 |
| White text | 3.07:1 |
Values
| HEX | #6599BC |
| RGB | rgb(101, 153, 188) |
| HSL | hsl(204, 39%, 57%) |
| OKLCH | oklch(66% 0.076 238.9) |
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 #6599BC | 3.07:1 | AA large text | Lc -62.9 | Content text, not long reading |
| Black text on #6599BC | 6.83:1 | AA | Lc 46.5 | Large or bold text, headings |
| #6599BC text on white | 3.07:1 | AA large text | Lc 57.5 | Large or bold text, headings |
| #6599BC text on black | 6.83:1 | AA | Lc -44.2 | Non-text elements, placeholder text |
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 500.
-
Step 50
50
#F2F6F8
oklch(97.1% 0.005 228.8)
-
Step 100
100
#E4EBF0
oklch(93.6% 0.01 238.5)
-
Step 200
200
#CDDBE6
oklch(88.4% 0.021 241.4)
-
Step 300
300
#ABC5D6
oklch(80.9% 0.037 236.6)
-
Step 400
400
#7EA6C2
oklch(70.6% 0.06 239.2)
-
Step 500
500 (this color)
#6599BC
oklch(66% 0.076 238.9)
-
Step 600
600
#417A9F
oklch(55.7% 0.083 239.1)
-
Step 700
700
#326788
oklch(49.2% 0.077 238.4)
-
Step 800
800
#2B546E
oklch(42.8% 0.063 238.5)
-
Step 900
900
#274559
oklch(37.6% 0.05 239.2)
-
Step 950
950
#172934
oklch(27.1% 0.031 236.4)
#6599BC 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) | #8998BE | 0.044 |
| Deuteranopia (no green cones) | #7E8FBB | 0.038 |
| Tritanopia (no blue cones) | #3FA2A4 | 0.061 |
| Achromatopsia (no color) | #939393 | 0.076 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #6599BC
#6599BC
oklch(66% 0.076 238.9)
- #B68763
#B68763
oklch(66.1% 0.076 58.4)
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 #6599BC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Greyblue #77A1B5 ΔE 0.036
- Faded Blue #658CBB ΔE 0.037
- Silver Lake Blue #778DA9 ΔE 0.040
- Blue Grey #758DA3 ΔE 0.044
- Cadet Blue #5F9EA0 ΔE 0.050
- Cool Gray #8D99AE ΔE 0.051
- Bluey Grey #89A0B0 ΔE 0.053
- Bluegrey #85A3B2 ΔE 0.053
Use #6599BC 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.