I purchased a set of 100% Italian cotton sheets that are very yellow. I want to make them as pale cream as possible. Should I use Clorox with hot or cold water?
Not sure that I have enough info to properly answer your question. It depends on what types of dyes were used to produce the yellow coloring. Some dyes are much more reactive with liquid bleach than others.
I would recommend doing this quick, simple Bleachability Test on any colored portion on a hidden part of the sheets, like a seam:
If there is color change this will help you gauge how much and what color you will attain if you choose to continue. You may not be able to get the “pale cream” color you desire with this approach.
If you choose to proceed, I would do a separate, warm wash with detergent using a milder than recommended amount of bleach (~1/2 cup) with only the sheets to minimize any dye transfer potential.