#647F99
Closest named color: Grey Blue (#647D8E). oklch(58.5% 0.051 247.7), rgb(100, 127, 153).
Aa
Black text reads best on this color (5.03:1).
About this color
#647F99 is a medium-dark, muted blue. In OKLCH its lightness is 59%, its chroma 0.051 and its hue 248°. Its hue sits on the cool side of the wheel. The nearest named color is Grey Blue (#647D8E), ΔE 0.017 away. Black text reads best on it, at 5.03:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | muted (0.051) |
| Temperature | cool |
| Nearest name | Grey Blue (#647D8E) |
| Black text | 5.03:1 |
| White text | 4.16:1 |
Values
| HEX | #647F99 |
| RGB | rgb(100, 127, 153) |
| HSL | hsl(209, 21%, 50%) |
| OKLCH | oklch(58.5% 0.051 247.7) |
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 #647F99 | 4.16:1 | AA large text | Lc -74.2 | Content text, not long reading |
| Black text on #647F99 | 5.03:1 | AA | Lc 35.4 | Non-text elements, placeholder text |
| #647F99 text on white | 4.16:1 | AA large text | Lc 68.7 | Content text, not long reading |
| #647F99 text on black | 5.03:1 | AA | Lc -33.0 | 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
#E6EAEE
oklch(93.5% 0.007 247.9)
-
Step 200
200
#D3DAE1
oklch(88.5% 0.012 248)
-
Step 300
300
#B5C2CF
oklch(80.8% 0.023 248.1)
-
Step 400
400
#8FA3B7
oklch(70.7% 0.037 248.3)
-
Step 500
500
#738DA5
oklch(63.2% 0.047 246.5)
-
Step 600
600 (this color)
#647F99
oklch(58.5% 0.051 247.7)
-
Step 700
700
#4B637B
oklch(49% 0.048 248.8)
-
Step 800
800
#3E5164
oklch(42.7% 0.04 248.8)
-
Step 900
900
#354351
oklch(37.6% 0.03 248.6)
-
Step 950
950
#1F2730
oklch(26.9% 0.02 251.6)
#647F99 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) | #757F9A | 0.023 |
| Deuteranopia (no green cones) | #6E7A98 | 0.018 |
| Tritanopia (no blue cones) | #538587 | 0.043 |
| Achromatopsia (no color) | #7C7C7C | 0.051 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #647F99
#647F99
oklch(58.5% 0.051 247.7)
- #90775B
#90775B
oklch(58.6% 0.051 69.7)
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 #647F99, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Grey Blue #647D8E ΔE 0.017
- Slate Gray #708090 ΔE 0.021
- Stormy Blue #507B9C ΔE 0.028
- Steel #738595 ΔE 0.029
- Battleship Grey #6B7C85 ΔE 0.030
- Steel Grey #6F828A ΔE 0.030
- Dusty Blue #5A86AD ΔE 0.032
- Off Blue #5684AE ΔE 0.033
Use #647F99 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.