Just like Gmail, Google Docs forms now have themes. All you have to do is click on the "Theme" button which will lead you to a list of themes ranging from standard color arrangements to flashy designs.
I am so happy they added this feature. I use forms to gather student feedback for the labs that I teach, it's a great way to collect information in an environmentally friendly way (no paper woohoo). The original form theme (there was only one of them) was very dull and boring, now I can make the form more visually appealing which should increase the response percentage. Great feature.