Going into the webdev laboratory (i.e. pressed F12) to see how color-mix() in CSS works with getComputedStyle(). Can it simply get you the fully computed colour? It seems: yes, it can! But it's in the format of the color model you mixed with.
They're adding a CSS value called "pretty"? That's the best name they could come up with? The text wrapping is "pretty"?? Why not give up the pretense and call it "good" or "epic" or "awesomesauce" or something