#647A8A
Closest named color: Grey Blue (#647D8E). oklch(56.8% 0.036 239.8), rgb(100, 122, 138).
Aa
Black text reads best on this color (4.69:1).
About this color
#647A8A is a medium-dark, muted blue. In OKLCH its lightness is 57%, its chroma 0.036 and its hue 240°. Its hue sits on the cool side of the wheel. The nearest named color is Grey Blue (#647D8E), ΔE 0.009 away. Black text reads best on it, at 4.69:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | muted (0.036) |
| Temperature | cool |
| Nearest name | Grey Blue (#647D8E) |
| Black text | 4.69:1 |
| White text | 4.47:1 |
Values
| HEX | #647A8A |
| RGB | rgb(100, 122, 138) |
| HSL | hsl(205, 16%, 47%) |
| OKLCH | oklch(56.8% 0.036 239.8) |
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 #647A8A | 4.47:1 | AA large text | Lc -76.5 | Fine for body text |
| Black text on #647A8A | 4.69:1 | AA | Lc 33.0 | Non-text elements, placeholder text |
| #647A8A text on white | 4.47:1 | AA large text | Lc 71.1 | Content text, not long reading |
| #647A8A text on black | 4.69:1 | AA | Lc -30.6 | 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
#F4F6F7
oklch(97.2% 0.003 228.8)
-
Step 100
100
#E7EAED
oklch(93.6% 0.005 247.9)
-
Step 200
200
#D4DADE
oklch(88.5% 0.009 236.6)
-
Step 300
300
#B8C2CA
oklch(80.9% 0.016 241.8)
-
Step 400
400
#93A3AF
oklch(70.7% 0.025 240.2)
-
Step 500
500
#788D9C
oklch(63.2% 0.033 239.2)
-
Step 600
600 (this color)
#647A8A
oklch(56.8% 0.036 239.8)
-
Step 700
700
#506472
oklch(49.2% 0.033 238.9)
-
Step 800
800
#42515D
oklch(42.7% 0.028 242.5)
-
Step 900
900
#37434C
oklch(37.6% 0.022 240.6)
-
Step 950
950
#21272C
oklch(26.9% 0.013 243.3)
#647A8A 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) | #73798B | 0.021 |
| Deuteranopia (no green cones) | #6E758A | 0.019 |
| Tritanopia (no blue cones) | #597E7F | 0.028 |
| Achromatopsia (no color) | #777777 | 0.036 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #647A8A
#647A8A
oklch(56.8% 0.036 239.8)
- #877262
#877262
oklch(56.7% 0.036 59.3)
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 #647A8A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Grey Blue #647D8E ΔE 0.009
- Battleship Grey #6B7C85 ΔE 0.015
- Battleship Gray #6C757D ΔE 0.022
- Slate Gray #708090 ΔE 0.026
- Steel Grey #6F828A ΔE 0.029
- Stormy Blue #507B9C ΔE 0.034
- Metallic Blue #4F738E ΔE 0.037
- Steel #738595 ΔE 0.040
Use #647A8A 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.