Hi, I noted that the Color conversion of RGB to HSL isn't quite right - in particular the .l() or Lightness is consistently too high.

Fantom Shell v1.0.79 ('?' for help)
fansh> using graphics
Add using: using graphics
fansh> Color("red").l
1.0

Whereas the luminosity of red should half that at 0.5. If using graphics::Color then the hsl of red actually produces white - e.g. hsl(0deg, 100%, 100%).

I know the maths behind RGB to HSL can get a little complicated but it'd be very useful if the formula used could re-visited.

For instance this article suggests luminance may be calculated as follows:

Now calculate the Luminace value by adding the max and min values and divide by 2.

Whereas the current algorithm only takes the maximum value.

Yeah that doesn't look right - we'll take a look.

Ticket promoted to #2909 and assigned to andy

Ticket resolved in 1.0.80

HSL behavior should now match browser implementations.

Brilliant - thanks Andy!

Could you reference the formulas used in the conversions?