Have you tried Niagra Spray Starch? Not sure if it comes in any other form than the spray, my mother used it all the time and I have as well on occasion, have never noticed a color change with any items.
Hope that helps,
Katbird

Moonbug - Take a look at the link below - several products are described and whether or not they will yellow over time...

Here is a link that might be useful: Starching Techniques

The sugar syrup is the old method, and works just fine. You can rewash with that one. The Elmers glue and water will work fine for making ornaments and angels that you may never want to do over again. I have used both on things like baskets with handles and a crocheted swan basket...also a crocheted vase.

Thanks Millie for the info. I've never used the glue/water type, how does it go, how much glue, how much water ? Does the item get yellow? Sounds like something I'd like to try.