It would be very helpful in heavy modded server where there is many items in the chest or in the inventory to be able to search for them by their names instead of trying to find them for minutes. I don't know if it's possible to make it but suggesting is not wrong so why not ask.

If you use NEI, try double click on NEI search bar. It's border will turning to yellow, and type the item or block you want. After that if you looking to inventories and containers, every not matched entry will be shaded darker. So what you searching will be highlighted with this method. After searching double click to search bar to turn off highlighting.