I understand you like the color scheme you have used, but can you share why you think the modified color scheme is more "beautiful" ? which Phet applet are you referencing from? Or is it your own design color?
I always thought the beauty of the applet is in the design of the various physics quantities that are commonly learnt in A level physics but no coherent applet to incorporate the physics ideas like "force, velocity, acceleration displacement, the 7 graphs etc" ;D I will re-look the applet and release a even better looking version soon!
Thanks for the g chat to understand your thoughts ;)