Pecan and Hickory belong to the same (Carya) family and therefore they are extremely similar. There are more types of Hickory than Pecan and Hickory grows in more places but they do get separated and it is possible to get one or the other. The most common look that we are asked for is a medium to light brown tone and most of the time its Hickory. I associate the darker reds and brown or white sap with Pecan. We do keep some of both species in stock but usually show mill samples for projects that require large sequences and specific appearance. When we make architectural panels we clip sap away and use heart. We had a spec for white Pecan one time and actually found a Pecan flitch that was almost entirely sap to satisfy it. The sequenced cut to size panels were actually very white!