Just get a random free base from DeviantArt, and go to Kleki, use random colors from there, then if you don't like the colors you chose when you finish, you can just go to "Edit" and click on "Hue/Saturation". and then you can mix and match different colors that way to pick your own liking
(Eg: https://www.deviantart.com/mitsuki-wolf/art/Dutch-Angel-Dragon-Free-Base-656969068)