If subtle is what you're after, then why be concerned with a logo ??
If one has enough business, that they don't need to attract anymore, why worry about looks, colors or anything aesthetic ??
Other than well marketed companies or well established businesses, subtly is usually not your friend, regardless if you're in England or Africa. Becoming known can only be achieved a few ways, and blending in with your surroundings generally isn't one of them. If we were talking about doing interior decorating in your shop, then, subtleties work well.