What the rule should do: Report invalid values for the red/green/blue (0-255) and alpha (0-1) values of the rgb(a) functions. Similarly it should also report invalid values for hsl(a), these should all be between 0 and 1.
What problems does it solve: Introducing invalid color values using the functions rgb, rgba, hsl and hsla.
Example of things the rule would report:
CSS.Types.Color.rgb({ red : 300, green : 300, blue : 300 })
CSS.Types.Color.rgba({ red : 300, green : 300, blue : 300, alpha: 1.3 })
CSS.Types.Color.hsl({ hue : 1.3, saturation : 1.3, lightness : 1.3 })
CSS.Types.Color.hsla({ hue : 1.3, saturation : 1.3, lightness : 1.3, alpha : 1.3 })
Example of things the rule would not report:
CSS.Types.Color.rgb({ red : 255, green : 255, blue : 255 })
CSS.Types.Color.rgba({ red : 255, green : 255, blue : 255, alpha: 1 })
CSS.Types.Color.hsl({ hue : 1, saturation : 1, lightness : 1 })
CSS.Types.Color.hsla({ hue : 1, saturation : 1, lightness : 1, alpha : 1 })