Do not use .dict.dz files
I encountered the problem when I stored a self-made stardict dictionary file to my Android. All I got to do was just not to use a compressed file of stardict .dict.dz file but to convert .dict.dz file to uncompressed a .dict file because ColorDict does NOT support compressed stardict file. When you a compile a text file to stardict file on Linux OS, the .dict data must be compressed to .dz.
Use stardict-editor to decompressed .dict.dz file on Linux using decompile tab and follow the message showing in the window.
With Nexus 5, .dict.dz file was automatically decommpressed.
With Nexus 9,it wasn’t. I don’t know why.