I am currently using Affinity Designer for graphics and Axure RP9 for prototyping.
What I need to do now is definition of UI elements. I need changes in certain elements to be reflected for others. For example when I change colour of checkbox I want checkbox to change in all elements that include it.
I am not sure if Axure or Affinity is capable of this. If not, what would be good application to fit well with Affinity Designer and Axure RP9 and icludes this feature?
Yes! Both have features to support reusable components.
In Affinity Designer you have Symbols that can be used to create reusable UI elements within a single document. For export/import you can use Designer’s Assets which is really nice since you can categorize them, and put them in a shareable design library. (Serif Forum Post)
Axure RP also has similar concepts. In Axure you have Masters and Libraries. Masters work like Symbols above. You can convert a component in the Axure project into a Master, then edit the Master at any point and it will update all instances of that Master across the project. A Library is similar to Assets above. You can create and export your own libraries to use across projects or import/purchase 3rd party libraries. The big difference between Libraries and Masters are if you edit a library element, it won’t change other instances of that element elsewhere in your project. A Master if you used it in pages A & B, and edit the master in page A, then the master in page B will also be updated.