I have an unusual icon theme on my computer (which is specifically designed for regular computers and not necessarily smaller devices). It's almost completely monochrome, grey to be exact, although you can select the colour yourself. The reason I want all icons to have the same colour, isn't that it looks good, although it does, or that it removes distraction, although it does, it's because colourful icon themes is bad UX design. I'm more senstive to colour than shape, hence the description of subpixel rendering on text looking like someone sprinkled glitter all over the text feels apt. This means that removing colour from icons remove their most prominent feature, which is good in this case because many icons share similar colour making it easier to click the wrong icon by mistake because they look similar. Another failure of colourful icon themese is that warning colours fail to draw your attention, this is why may icon theme only uses colour when it needs to draw your attention, when the user has specified a colour to mark an object into some user defined category.