If Iron makes blood red then what metals would make other colors?

I don't think it's red because of the iron. It's Oxy-Haemaglobin that makes it red. When the oxygen disappears, it goes a darker red, but never blue.
Mr. Spoks blood is purely fictional, and could be any colour.
I think blood is always red. If your's turns a different colour, then you can start worrying.

metals supply ions and it is the ions which yield the colours in various substances. Flames can be coloured by the addition of metal salts, precious jewels are coloured by the inclusion of metal ions. The same is true for coloured glass which is found profusely in stained glass windows in cathedrals around the world. Different metals yield different colours. Gold for example will lend a beautiful purple colour to glass, iron makes the glass green, cobalt gives it a violet/blue colour, and so on. Copper sulphate is coloured aqua by the copper ion.
The purpose of iron in blood is to capture the oxygen from the lungs. When iron is exposed to oxygen in the outdoors, it forms 'rust' (ie., iron oxide). Weathered copper will form a greenish patina instead. The molecular structure of blood is composed of the atoms of carbon, hydrogen, oxygen, and nitrogen plus the iron. Chlorophyll in plants is almost identical to red blood but it is green because the iron atom is replaced by magnesium.

Many molluscs have copper instead of iron in their blood, and their blood is blue. They have different physiologies, though, so copper works for them, but iron would not. We just happen to use iron, which has worked best for us over time.

Haemoglobin is never completely blue. Deoxygenated haemoglobin has a darker red to purple colour, but it is not completely blue, despite what our veins look like. And it is not just the metal ion that colours the blood. Remember that it is bound to a protein, and these complexes can exhibit different colours than the free metal ion. Iron(III) chloride is bright yellow, for example, whereas iron(II) chloride is green, yet our blood is red. So it is not just due to the presence of iron ions.