can you order one knob to try out and return it if it doesn't fit? or if you're willing to wait until you get your new wall oven, pull one of those knobs off and see if it fits.

I don't know if they are universal but have you priced them out? Not cheap.

are you able to see your bluestar range in real life right now? pull a knob off your GE range, bring it to the store, and see if it fits on the bluestar. if the GE knob fits, then you'll know they're compatible.

this is what's happening under a bluestar knob. it looks like the bezel is removable too, so you might need to get bezels and knobs to get this to work.

(edit: I just realized the shaft in this picture is broken, so don't look at that part.)

Knobs are indexed to the shape of the control shaft to orient accordingly to labeled positions on the panel. Diameter and shape of control shafts vary from brand-to-brand and possibly from model-to-model within a brand. Whether Bluestar knobs will fit on your GE is a matter of trying it, or observing the components beforehand for any differences ... and whether it's a problem for you if they do fit but are misoriented.

Honestly, if I visited your kitchen, I would not care if the knobs were different colors. No one is going to say “that’s it! Different knob colors, I’m outta here!”. Most people won’t notice, nor will you after a week.

You could also get the Bluestar wall oven’s stainless steel knobs which go with everything. That is the easiest solution.