Yellow shea butter is known to be strong because this is the unrefined version. You may find some impurities, but this will only be obvious when the butter has not been properly filtered. White shea butter is known to be unrefined shea butter. This has already passed through a filter so that its impurities can be properly removed. If you would like to have shea butter that has different moisturizing capabilities, then you can choose any type of shea butter, but if you are searching for something that has vitamin content, then you know that you need to choose yellow shea butter over the white one.