Bread is brown. It's white with unnecessary additives. If you buy breadcrumbs for such purpose, they're always light brown or wholemeal. There's no point in fluffy white flour being used which arguably cooks worse with meat cooking methods as it's finer.

If the meat's distinctly yellow, it is likely oil too, rice bran oil is common as it's quite flavourless and results in strong colour, like conola oils. Oil is used to have crumbs stick on meats that have had their fats/bloods well drained. These are usually cuts not reserved for top quality cooking where the meat is preserved as the pinnacle for the dish, rather than meats being added to the dish or being part of the dish.

Source: Not a butcher, but big into slow cook and BBQ, so deal with a lot of cuts and prep.