Android Question Generate Random Text Colors For a White Background

DPaul said:

1) I think you should change 256 into 255, there are only 255 shades plus zero. (total = 256)

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Syd Wright said:

Put these RGB values in an array and select one at random.

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• White color is 255,255,255.
• Any color with "high" RGB values will be more similar to white, that's clear. So it makes sense to limit them somehow. The key here is how to limit them.

• Not all the components (R,G,B) play the same 'role' in human lightness/luminance perception. That's why luminance, in different models is calculated as a weighted sum of all the components. The assigned weights vary between models, but most of them give a much higher weight to the green component.
• As a very rough approach, you could start using 0.25,0.5,0.25 (as said, green is the one that most contributes to luminance).
• Then, you could limit the total lightness to, for instance, 180

Sub GenerateDarkEnoughColor( maxAllowedLuminance as Int) as int
  Dim R,G,B, luminance as int
  Do until luminance<=maxAllowedLuminance)
    R = rnd( 0, 256)
    G = rnd( 0, 256)
    B = rnd( 0, 256)
   luminance = 0.25*R + 0.5*G + 0.25*B   
  Loop
  return Colors.RGB(R,G,B)
End Sub

'call the function with this
myColor = GenerateDarkEnoughColor(180)