Laravel: Trying to detect a range of hex colors

Question

I am trying to refrain from using a library to do this but I am sending a method a hex color as a string and I'd like to determine if it's a white (or near white) color and if so throw an exception.

$color = $request->input('color') // '#FFFFFF'

doing so for white ( like above ), or any single color, would be pretty self explanatory but I can't figure out how to map out a bunch of light colors without explicitly creating an array with every light color

Not for nothing, but the comment in your code has `// '#000000'` which is black, not white (which would be `#FFFFFF`). — Wesley Smith, Oct 19 '20 at 18:18
https://24ways.org/2010/calculating-color-contrast/ you can also check via color contrast towards white. — Dark Knight, Oct 19 '20 at 18:39

Alex Barker · Answer 1 · 2020-10-19T19:12:25.660

0

There are probably 100 ways to do what you are asking, this is the first that came to mind.

$color = "#FAFBFE";
$numVal = hexdec(substr($color, 1));

$red = ($numVal & 0xFF0000) >> 16;
$green = ($numVal & 0xFF00) >> 8;
$blue = $numVal & 0xFF;

if ($red >= 225 && $green >= 225 && $blue >= 225) {
   // Close enough
}

edited Oct 19 '20 at 19:12

answered Oct 19 '20 at 19:02

Alex Barker

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Laravel: Trying to detect a range of hex colors

1 Answers1