looking to spruce up front calipers but undecided on colour... Reddish blue classic and was thinking of black or red what do you think would suit

 

Red. Use hammerite smooth, applied by brush.
Don't forget to buy some Hammerite thinners, not much else will clean the brush, which will dry rock-solid between coats without cleaning

 

ive got the same color scoob, where can u get the paint from?

 

Most car shops, Hell-Frauds, B&Q, Homebase, etc, sell hammerite. Look for the smooth type. Buy the smallest can available, it'll easily do all 4 calipers on your car, with enough left for a repaint if needed later.