Do you want these or those? is not about the pens' colour. It is about how near or far the pens are - whether they are within your reach or not. At least this is the distinction I could make out of context.
PS. Cross posted with Perp, who is playing it safe, suggesting that the colour be mentioned. He is right, of course.
I agree with perpend and boozer. I'll just add that these means that the pens, regardless of their color, are either in my hand or close by. Those means that the pens are farther away. How much farther away isn't important so long as you make a clear contrast.
This question might be adequate and understandable and OK in proper context. I agree with Boozer and Quality, but I just want you to understand that gestures and placements of the pens are at issue. IF the blue are at hand, and you gesture to them, and the red are not, and you gesture toward those, THEN the sentence fits and is fine.