JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
If you want to change the Theme of your form, you can change it from Preferences > Form Styles > Themes.
If you are referring to a different concern, can you provide to us the link or name of the form in question and the theme you want to implement on your form so we can further check the issue?
We will wait for your response.