We just had our white oak floors sanded and refinished and are ready to apply the last protective coat. We used Bona natural stain and there seems to be unnatural variation in the color of the wood. I expect variation in uptake due to the grain of the wood and normal variation, but some of the areas look like it could be related to poorly applied finish. my contractor reassured me that this was all within the normal range of variability, but I didn't notice this before our floors were refinished although the overall appearance was darker so it may not have been as noticeable.