Php convert string to hex color

I agree with sje397 above that completely random colours could end up looking nasty. Rather than make a long list of nice-looking colours, I would suggest choosing a constant saturation+luminescence value, and varying the hue based on the content. To get an RGB colour from an HSL colour, you may use something similar to what's described in //en.wikipedia.org/wiki/HSL_and_HSV#Converting_to_RGB .

Here's an example [try it in //codepad.viper-7.com something that works, such as //codepad.remoteinterview.io/ZXBMZWYJFO]: