This is ridiculously simple to fix and you don't even need SSH.
1. Download iFile. It's shareware so you could use it for free.
2. go to /var/stash/Applications/MobileSMS.app
3. look for Icon-Small.png,
Icon-Small@2x.png, icon.png and
icon@2x.png, click edit and then the little arrow in the lower right, then --> copy
(you might not need all 4 but this is what I did and it works perfect.)
4. go to var/stash/Applications/biteSMS.app and select edit and then paste.
5. reboot/respring
Bam, you have just replaced the ugly pink icon with the nice default apple retina one. Total time invested 5 minutes if you include installing iFile from a slow ass cydia.
tl;dr: copy the icons from your MobileSMS.app app into BiteSMS.app