Black may well be the new black but, at least until dirty green achieves similar status, those of use who want to use the otherwise very nice Twenty Fourteen theme can surely appreciate this plug-in. It's not a mere color picker, as it will also calculate other matching colors to accompany the choice you've made. That is good. Where it could be better though is if it still allowed the user to change some of the secondary colors, such as the one called 'accent_dark'. The source code comments itself say (color-patterns.php:364):
// Darken the accent color, if needed, for adequate (4.5:1) contrast against white page background.
// Unfortunately, this can result in some colors losing character, such as yellow -> gold.`
It was really funny to read the above comment in the source code when I went on to edit it by hand because I ran into exactly the situation described. Already a solid five-star but hopefully the author considers allowing us to override more colors in the future versions. It's my website after all, and ruining it with an ugly color scheme should be my statutory right.