Appearently the cabinets already have the crown and you want to do the rest of the room to match, Right? The crown on the cabinets was probably prefinished but you can get a close match if you take a sample to Home Depot or other large store. It will not hurt to be just a shade off when you go past a corner; I'm sure you can take a close look at the crown you have and it will show different colors at corners. Its just the way the light hits it. Unless yours is an odd shape you can probably buy more at the same place that matches the stain.