If the cartridges you have removed from your printer were original brand type and the ones you have purchased are a generic type, there will be some subtle design differences between the cartridges.
Such differences are necessary so that copyright is respected and not infringed by the manufacturer. Also, compatible cartridges are designed to fit various printer models rather than just one printer.
You can be confident though that such differences should have no impact on the use and functionality of the cartridge. If you do see a difference, firstly check the model code label that is attached to the printer cartridge itself and ensure that such is correct and is the same as the one removed.