I just came across this issue myself. With Amira footage in 2015, Premiere automatically adds a LUT to each file that you cannot disable/delete. You can only toggle it off use the fx switch in the Master Effect panel. It also seriously bloats the size of the project.
My workaround (for now) is to import everything into a new project in Premiere and export it as an XML. Then I import the XML into my actual project. The LUTS are stripped out, and the project file drops significantly (I saw a file reduce from 150MB to 1MB).
If you still need to apply the Amira LUT, apply one to the master effect of a clip, copy it in the Master Effect panel, select all the clips in your project panel and paste. This does not bring the project back up to its original bloated size.