#647C99
Closest named color: Grey Blue (#647D8E). oklch(57.8% 0.053 253.4), rgb(100, 124, 153).
Aa
Black text reads best on this color (4.88:1).
About this color
#647C99 is a medium-dark, muted blue. In OKLCH its lightness is 58%, its chroma 0.053 and its hue 253°. Its hue sits on the cool side of the wheel. The nearest named color is Grey Blue (#647D8E), ΔE 0.019 away. Black text reads best on it, at 4.88:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | muted (0.053) |
| Temperature | cool |
| Nearest name | Grey Blue (#647D8E) |
| Black text | 4.88:1 |
| White text | 4.29:1 |
Values
| HEX | #647C99 |
| RGB | rgb(100, 124, 153) |
| HSL | hsl(213, 21%, 50%) |
| OKLCH | oklch(57.8% 0.053 253.4) |
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 #647C99 | 4.29:1 | AA large text | Lc -75.2 | Fine for body text |
| Black text on #647C99 | 4.88:1 | AA | Lc 34.4 | Non-text elements, placeholder text |
| #647C99 text on white | 4.29:1 | AA large text | Lc 69.7 | Content text, not long reading |
| #647C99 text on black | 4.88:1 | AA | Lc -31.9 | 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 600.
-
Step 50
50
#F4F6F8
oklch(97.2% 0.003 247.9)
-
Step 100
100
#E7EAEE
oklch(93.6% 0.006 255.5)
-
Step 200
200
#D3DAE2
oklch(88.5% 0.013 251.6)
-
Step 300
300
#B6C2D0
oklch(80.9% 0.024 252.2)
-
Step 400
400
#90A2B8
oklch(70.6% 0.038 253.5)
-
Step 500
500
#758CA7
oklch(63.2% 0.049 252.7)
-
Step 600
600 (this color)
#647C99
oklch(57.8% 0.053 253.4)
-
Step 700
700
#4D637C
oklch(49.2% 0.048 252)
-
Step 800
800
#3F5065
oklch(42.6% 0.041 254)
-
Step 900
900
#364352
oklch(37.8% 0.031 252.3)
-
Step 950
950
#202730
oklch(27% 0.02 254.8)
#647C99 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) | #717D9A | 0.018 |
| Deuteranopia (no green cones) | #6B7898 | 0.014 |
| Tritanopia (no blue cones) | #548286 | 0.044 |
| Achromatopsia (no color) | #7A7A7A | 0.053 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #647C99
#647C99
oklch(57.8% 0.053 253.4)
- #8D7557
#8D7557
oklch(57.7% 0.053 72.7)
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 #647C99, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Grey Blue #647D8E ΔE 0.019
- Stormy Blue #507B9C ΔE 0.025
- Slate Gray #708090 ΔE 0.026
- Battleship Grey #6B7C85 ΔE 0.032
- Off Blue #5684AE ΔE 0.035
- Cerulean #457B9D ΔE 0.036
- Dusty Blue #5A86AD ΔE 0.036
- Steel Grey #6F828A ΔE 0.036
Use #647C99 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.