Comment by mediumsmart

Comment by mediumsmart a day ago

>But, on a large project, with a large team, carefully managing such details can become a really hard task to get right. Suddenly a dark button has unreadable black text, and users can’t figure out what to do.

Cant someone take a look at the buttons before the large project ships? Alternatively make it mandatory to never have black text on a dark button and tell every team member including the large ones.

Interesting to read about the perceptual contrast vs mathematical - I did not know that. Going to integrate that into my workflow.

Merad 7 hours ago

> Cant someone take a look at the buttons before the large project ships?

They can, of course, but this is how you end up with pre-release regression testing cycles that are weeks or even months long. A "large project" might easily have thousands of buttons (or more!), many of which are only seen when certain settings are enabled, certain options are chosen during a complex workflow, etc.

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johnisgood a day ago

You may want to read about APCA, as you can have perceptual contrast calculations using the APCA algorithm.

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refulgentis a day ago

You can have them with WCAG2, the stock APCA example hides the ball significantly and leads to a lot of incorrect conclusions in the article (tl;dr: black has more contrast by either measure, its just that APCA says you don't need as much contrast, so you can use white and have sufficient contrast)

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- csande17 15 hours ago
  
  > black has more contrast by either measure
  No it doesn't? The screenshot of the calculator in the blog post very clearly shows that white has a greater contrast according to APCA. (If the negative numbers are confusing, you can also put the colors into a BridgePCA calculator like https://www.color-contrast.dev/?txtColor=FFFFFF&bgColor=317C... to see WCAG-2-style "contrast ratio" metrics computed using APCA.)
  The point of APCA is to make the contrast calculation more perceptually accurate, not just lower the threshold.
  
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- johnisgood a day ago
  
  I know about WCAG, too. You can also just implement a function that detects whether or not a color is dark or not. It is a general purpose function, e.g. my "isDark" function is: "func() < 0.5" (func() is omitted, but it is an algorithm). You can have "isLight", too, by doing "> 0.5". There are many ways to do this. You can just simply convert a hex color to RGB, then compute the luminance of the color, and then compare the luminance to a threshold (e.g. 0.5) to classify it as dark or light. The luminance function (WCAG luminance formula) converts RGB values to the range 0-1, applies gamma correction, and calculates luminance using the weighted sum of the gamma-corrected RGB values.
  > APCA says you don't need as much contrast
  You can always specify the threshold if you want, e.g. "apcaContrast(color)) >= $targetContrast" after adjusting, depending on what you want to do.
  It really is easy, just make sure you have enough color space.
  
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  refulgentis a day ago
  
  The WCAG luminance formula (relative luminance in color science terms) has perceptual mid gray at 0.18, not 0.5.
  re: just change APCA contrast target, that's separate from the Not Even Wrong stuff in the article. I didn't mean to imply APCA is wrong to say you need less contrast, but rather, that the article is wrong to conclude white has more contrast.
  
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- mediumsmart a day ago
  
  I thought the white looks sharper but is not really. I would darken the blue a bit to be happy about it.
  
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