Add new theme switcher named colors

Why I chose these colors: Blue is the most popular color. Both, men and women like blue. I think it's more important that most people simply like blue than the psychological effects of other colors who might be better according to Color Psychology by Nick Colander. That's why I decided not to use a color like orang that would be the color to use according to the table below. On the other hand blue is a color that achieves a relaxed mood. Thats what we want. I also chose white for the Text because it's good to see on a blue background and kind of a neutral color. Red and green for correct and wrong answers are the right decisions so I also use these colors. I made the "Format" -button dark blue so its better to see in front of the light blue background. I chose the blue color for this button because it's better to use less colors than too many. I tried to use less colors as possible for "ARSnova.click" because a website should not be too colorful according to "Color Psychology".

Some pictures of the new theme switcher:

Quizmaster:

Candidate: