Wire source for custom harness

[Canyonero]

Is there somewhere I can buy spools of wire in color combinations to match my wiring harnesses? I'm in the process of integrating a standalone harness into my chassis wiring. I have things temporaried now, but I'd like to have the permanent wiring match a little better.

I might do the wiring from scratch for my next project, so it would be good to have a source for connectors too.

Thanks!