Colonizers rhymes with:
ionizers, organizers, ionizers, organizers, advertiser's, advertisers, advertisers', analyzers, appetizers, exercisers, fertilizers, franchisers, ionizers, itemizers, merchandisers, mobilizers, organizers, rittereiser's, stabilizers, sterilizers, supervisors', sympathizers, synthesizers, tranquilizers
Colonizers sounds like:
challenger's, challengers, cleansers, clunkers