Nice colours and changes and so forth

how do I make the new glyphs look like this? I like those colours.

also: is there a handy list of what is new/changed in version 3?

The illustration above is a stylized rendering of the Glyphs app. The blue tint in the illustration is not possible in the real app. You can, however, change the accent color of Glyphs.

The announcement blog post has lots of details on the new features of Glyphs 3.