new afterwards. If possible, go online and pull up a YouTube clip showing a power washing for fences, steps, etc., there's just about everything out there in Internet land.

It is amazing what it can clean. Also, consider using "deck brightening" solution.

We did steps and major amounting of fencing last summer, staining it all. This website is very useful for tips when it comes to wooden decks, steps and fences: https://www.deckstainhelp.com/

Any type of soap/bleach can be difficult to get completely off and turn into a majore slip hazard.

I have an assortment of Minwax stains. Wiped the new board with Walnut stain. It was a little darker at first but lightened after a rainstorm 2 days later. Looks just about the same as the old boards now. I did just one light coat. There are many color options available, I just used what I had. You can get Minwax in 8 oz cans at Ace hardware in my neck of the woods.

Or clean the old ones. Put washing soda in a watering can, slosh it on the boards, scrub with a broom, rinse. Water repellent is usually recommended. If the old ones are very old, they could be the old type of pressure treated. It was toxic so they replaced it with the new type. The color may never quite be a total match.