Hello Muhib Methani,

there are several methods to help you to change type:

1, you can just drag the swc file into vaa3d, Ctrl-L to enter the line mode, and selete any curves,choose Alt-T, there will be a dailog to let you choose the color you want;

2, you can just write an python script, change the second column of swc files, the each row of swc files means (n type x y z r parent), change type you wanted.

If you have anyother problems, please tell me. 

Best wishes,

Lingli