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Suppose you have a transparent color in R: "#00BFFF4C". How to find the non-transparant color such that it looks the same on a white background?

Ruben
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  • It will just be 4C/FF times 00, BF and FF, presumably. i.e. #00394C00, approximately. – Andrew Gustar Jul 16 '19 at 08:37
  • remove the last two values from the alpha channel ...i,e, `#00BFFF` ; check `scales::alpha("#00BFFF", 0.3)` – user20650 Jul 16 '19 at 08:39
  • I am sorry user20650, but that is not correct. What you propose gives a darker color than the transparent color. – Ruben Jul 16 '19 at 08:45
  • @AndrewGustar It seems reasonable that it would be like that, but the color you propose doesn't like the transparent color in the question. – Ruben Jul 16 '19 at 08:54
  • @Ruben Ah! Actually, FFFFFF is white, so you need to work backwards, and apply the 4C/FF factor to (FF-00), (FF-BF), etc, and then subtract that from FF again. Can't do that in my head in this cafe, but hopefully that helps! – Andrew Gustar Jul 16 '19 at 09:55
  • Thank you very much, I now also understand how making lighter and darker works with rgb color coding. – Ruben Jul 16 '19 at 11:25

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