White Balsamic Vinegar No White Balsamic Vinegar!!!!?

No White Balsamic Vinegar!!!!? - white balsamic vinegar

I have three different stores, and I can not find white balsamic vinegar! My recipe calls for 1 / 4 cup, is there a substitute I can use? In the mixture with orzo and I do not really use the brown vinegar. You can simply skip the vinegar all together ... or can I mix a little balsamic vinegar plain white ... or I only use rice vinegar? Help!
Thank you!