Fix JS API legacy SassColor.change

[ntkme]

Changing a non-rgb legacy color's red channel works with a deprecation warning, but changing its green or blue channel fails:

> SassColor({ hue: 1, saturation: 1, lightness: 1 }).change({ red: 1 })
DEPRECATION WARNING: Changing a channel not in this color's space without explicitly specifying the `space` option is deprecated.
More info: https://sass-lang.com/d/color-4-api

hsl(179.9665650506, 43.2680443077%, 0.691245098%)

> SassColor({ hue: 1, saturation: 1, lightness: 1 }).change({ green: 1 })
Uncaught Error: `green` is not a valid channel in `hsl`.