Acording to the GM order guides the sales code IS 43U other GM yellows used (not on the twins) are 52U and 34U and several fleet colors that don't have sales codes
EDIT: the **U / **L are sales codes the actual paint mix/application code is the longer number. Our TrailBlazer carries the sales code of 50U and a mix number of BC/CC U8624. The 50U code stands for the white paint as a sales code but the BC (basecoat) CC (clearcoat) U8624 designates the type and application method. A vehicle built in another plant could possibally not use the basecoat/clearcoat or the same paint application method but the color would still be 50U. If a GM plant in South America built a vehicle with 50U as the sales code but it was painted with acrylic enamal the mix code would be different although the sales code is the same. I don't really know if GM uses more than one type of paint anymore bit the sales codes also give the public a code to use because Chevy, GMC, Pontiac may all paint a vehicle the same color but have a different sales name, so regardless of the sales name if it says 50U it is the same color.