Well, I believed it was pretty simple to do another colour version of my prototype… but no 
I’ve all my layouts in a page, and they are components.
I make all the links and declare all the behaviours for my prototype in another page with these components [I do this so my clients don’t see the other artboards evolutions]
When I duplicate the page (so everything) to create a second UI colour version,
I lose all the work done for the prototype!
Why? And How to do it?
Hummm…
I reply to my own stupidity 
You just have to select the first frame for the prototype then click on: 
and define the starting frame.
In fact all is kept, but you’ll see the links of the duplicate prototype only when trying to redo it.
It’s not so obvious
You can also ensure everything stays the same if you copy and paste all your frames into a new page, while in prototype mode. This makes it so everything you copied stays the same.
None of the above solutions are working for me. You can clearly see missing links in the duplicate version.
Tried copy+paste, duplicate, duplicate using mouse and option key and nothing works.
I am trying to duplicate the same thing in another page to create versions.
Sometimes some prototypes links aren’t displayed, but they exist.
Have you verified ?
I’m having the same issue as @Shweta_Srivastava . All the various suggestions for how to copy frames to a new page with prototype linking intact fail for me. Some are maintained, but most lost. This didn’t used to be an issue. I’ve also confirmed that the interaction links are indeed gone by switching to Presentation mode. This is a severe limitation or bug. Prototyping is a key reason for using Figma, but if you can’t move prototypes around, you get put into a box.
@Fred_Tinsel No, they aren’t working.
@Jim_Muirhead I found a hack for this. I have started using Figma branching. If you create a branch instead or duplicating, everything remains intact! 
Another workaround or hack is to copy prototype into a brand new file while in Prototype mode, then copy it back into the new page in your original file. All your interactions will be preserved.
@Shweta_Srivastava can you tell me more about how to remains prototype interactions in this case. i have the same mistake 
@Phuong_Dao I was duplicating the prototype to create versions and Figma has recently introduced ‘branching’. All the properties are retained in a branch. See if that works for you.
Check out this link on creating a branch.
Thanks! This was so helpful!
Is there a way I can duplicate a prototype as “separate” prototype? The current copy/paste still links clickable areas to original prototype. This prevents from duplicating the entire prototype as separate. It is also abnormally laborious to relink each clickable area to its destination copy. A simple right click option “Duplicate as new prototype” should do the trick? Is there a shortcut available?
I’d like to echo this – this did work for me.
As long as you copy into a separate file – not just a page! – it’ll retain all the prototype flows.
Worked for me when I coped my whole Section (which had a lot of Frames and prototype flows) into a new file, then copied that into where I wanted it to be in the original file.
