I want to change the colors of all buttons at once
If you want to change the colors of all buttons, you can go to General Settings, the tab Design and you will see that the first settings are the color settings for the whole menu.

I want to change the colors of just one button
First, click the button where you want to change the colors from at the admin dashboard. Then you see 'Button colors', press on the three colors you see to open a popup where you can change the colors of the button. When finished you press the button 'Choose' and save the settings.

I want to change the menu style
The default option is the the floating action buttons get on top of each other when the floating menu opens. But maybe you want them to open in a different way, for example in the shape of a semicircle. If you got to General Settings > Styling setting in the interface you can choose what Button Animation you prefer.

The following menu styles are available in the current version of Buttonizer:

Fade up (default)
Fade animation left to right
Circle animation