BTW objectivist. The problem with the redness of apples in philosophy is known as "qualia".

http://en.wikipedia.org/wiki/Qualia

The truth of colour is that it is light particles bouncing off surfaces and reaching our retina. This can be measured. But we're decades, (if we ever can) away from working out how the mind evaluates/experiences this. So if apples is red or not, can be contested in certain definitions of truth.

edit: I'm actually leaning toward that experiences, (like colour) can be measured objectively as you claim, it's just that it's quite possible that we will not be able to translate the achieved measurement to anything meaningful when we interpret it. But the important thing is that we'll be able to compare threshold values scientifically. So even if we won't ever understand how red an apple is to other people, we still can compare the level to different people, which is a huge leap in understanding subjective experiences.

I belong to the crowd who believe that we'll in the near future be able to build robots who experience the world and evaluate it, exactly like we do. Will love, think, reason and hope like we do. Anyhoo, this was a side note.