Scouts rip up colony ships. 1v1 the colony ship will win, but cost-wise there are many more scouts to a colony ship.
After doing a conversion for metal and crystal, a TEC colony ship costs 1125 credits, while a TEC scout costs a mere 200 credits. In other words, cost-wise you can afford about 5 scouts to every one colony frigate. Even after their damage nerf in 1.19, scouts are still pretty formidable when pointed against non-combat units like the colony frigate or siege frigate.
Also, Sin-related stuff belongs in the Sins forums, not off-topic