First Choice Livery
TOM based aircraft change every few days so its difficult to say, however if you are talking about this evenings flight to AYT then it is scheduled to be G-OOBI which according to Jethros is in Thomson Livery.
In-fact, according to Jethros there is only one B757 left in First Choice colours which is G-OOOX (which that is today flying out of LGW)
The only other aircraft in TOM's fleet that still are wearing the First Choice livery are:
1x A320 (G-OOAR) (usually MAN based)
2x A321 (G-OOPE/G-OOPH) (usually 1x MAN based and 1x LGW based)
6x B767s (all ex-First Choice) (G-DBLA/G-OOAN/G-OOBK/G-OOBL/G-OOBM/G-PJLO) which operate the Summer LH schedule out of LGW,MAN,BHX,GLA,BRS,NCL & EMA