Is it possible to implement dynamic themes for Mobilefirst 7.0 hybrid application? Requirement is like for different festivals theme color background of app etc .. will change is it possible? if possible documentation is available?
This has no relation to MobileFirst Platform Foundation 7.0.
While the provided solution generates for you an application skeleton, the main focus is on backend connectivity and security features, while what you are looking for is purely applicative.
You can implement this on your own using JavaScript. For example, check for the date and if the date corresponds to a date of a festival, then load different images for the application (the images will be already embedded in the app itself).
However, in MobileFirst Foundation 8.0 a new feature was introduced - Live Update. Using this feature you could very well manage these application UI changes from the server, per region, festival and so on... you will still need to implement some logic of the application UI on your own, of course.
Read more about Live Update: https://mobilefirstplatform.ibmcloud.com/tutorials/en/foundation/8.0/application-development/live-update/