Is there anything special that needs to be done when refinishing a deck that has 2 stain colors in it? We want it to look uniform through out.
If I understand correctly you have a deck which at two separate times has been stain two separate colors.
If this is the case, getting a single color will be difficult at best. Probably best to consider allowing the stain to fade for a couple of years, pressure washing and then trying to achieve a uniform coloring.