¿qué zapatos prefieres, los rojos o (those) otros blancos?

It should be "esos" because 1. "Otros"and "blancos" are masculine. (Match subject's gender) 2. Here is a trick: "this" and "these" have "t"s (esto, esta, estos, estas); "that" and "those" don't (eso, esa, esos, esas). 3. "Zapatos" is plural, so match the subject's number. 4. Remember to always match the subject's gender and number. Hope that helps!