[Lab] determine black or white color to draw text onto a CSS color browsing

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I made the most basic of functions to try to decide based on a CSS color background, what color to use for text on the background so it's not lost ( only black or white). The one below, seems to work for quick and dirty uses. It's just fun. But I know a lot more can be done mathematically with the r,g,b components. I tried a few silly things with sliders to filter the CSS colours also. Anyway have a gist here.
The function that I did is below. Yes, it's crap, but it sort of works if you have nothing else. Maybe someone with time on their hands can come up with something more exacting.

``````def safe_color(css_color):
rgba = ui.parse_color(css_color)
r = rgba[0]
g = rgba[1]
b = rgba[2]
if (((r + g + b) / 3 ) > .55) :
return 'black'
else:
return 'white'
``````

Output from gist

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Maybe `return 'black' if sum(rgba[:3]) / 3 > .55 else 'white'` ;-)

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Or `return 'black' if sum(rgba[:3]) > 1.65 else 'white'` ;-)

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`return int(sum(rgba[:3]) <= 1.65)`

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One tip for making text more readable is something the Material Design guidelines recommend: While white text should be `rgba(255, 255, 255, 1)`, but black text should be `rgba(0, 0, 0, 0.87)`. The slight opacity in the black makes it much more readable on colored backgrounds.

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`return int(sum(rgba[:3]) <= 1.65) or (0, 0, 0, .87)`

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Thanks guys. I have made a snippet for myself using
return int(sum(rgba[:3]) <= 1.65) or (0, 0, 0, .87)

I know it's not a big deal, but it's nice to have these things handy and to be a no brainer even if you ultimately tweak the colors. Will take a closer look at what @Webmaster4o did later , as I think he did some complimentary color work when he was working on themes.

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@ccc , I did try briefly to simplify the expression. I was trying to use unpacking, slicing didn't occur to me ðŸ˜±I didn't search stackflow, because I was playing with components also. But it seems like the average checked against a threshold seems to work ok. But I am glad you call us out on it. It does make me think before I post stuff. When I posted it, I was almost certain that I would be hearing from you. I was grinning for 5 mins when I saw your reply ðŸ˜¬ðŸ˜¬ðŸ˜¬

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Don't think toooo hard before you post to the forum... we love to see your crazy ideas in their raw form. But do consider running `Check Style` and `Analyze (PyFlakes)` as they find simple issues (like your unused variable) and push you to make your code more readable. I have become big fan of autopep8 on my Mac. It would be cool to see that level of automatic reformatting as an option in Pythonista.

Internal error.

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