Will this hose work for both coolant and boost applications?

Silicone handles both coolant loops and intercooler piping without issue. Temperature range and pressure rating depend on the specific hose wall thickness — test-fit in your application first to confirm clearance and flex radius.

What size clamps do I need?

You'll need hose clamps for each end. The 3.00" end takes a clamp sized for that diameter, and the 2.75" end takes one for that size. Grab one of each before you start assembly.

Can I paint or color-match this hose?

Red silicone doesn't accept paint adhesion well. If you need a different color, wrap it with heat-resistant tape or sleeve it — that's the reliable route. Painting silicone directly will chip and flake.