My first 3 sports jackets were all blue. The first was dark blue (but not navy) wool & silk. The second was 90 cashmere / 10 goat hair (again, not navy), and the third was a navy 100% cashmere. There is no mistaking either of these jackets so it really doesn't look like i'm wearing the same thing all the time.
It makes it really easy to mix and match when your sports jacket rotation is on the small side. To go with those jackets I had pants in light grey, medium grey, charcoal, mocha, and white linen, as well as light grey and charcoal flannels. Throw in a bunch of different shirts and you don't have to wear the same outfit for a long time.
Only after i've covered the basics did I start branching out. I've got a brown with blue windowpane and a medium grey with light blue windowpane on order with my tailor. I suggest you build-up your basics first and then start working on other things.