Is there any way to use a theme with a color blend on just some forms (or for example just the Rad message box) without affecting all the other forms that are using the same theme? In other words, do we have to create separate themes if we want the colors to vary for different forms?

Hello Ruth Goldberg,

Thank you for contacting us. Unfortunately there is a limitation in the current API, so you are correct you need to create a copy of your theme and change its name in Visual Style Builder. 

Greetings,
Nick
the Telerik team