Streaks on venetian plaster

Cleaning a high end residential home that has a Venetian plaster (like a real smooth stucco finish). It is not paint but similar to dryvit where the color is tinted into the material and applied. There is a lot of expensive landscaping around the walls around the property and so what I did was buy 4 small spray bottles and made up differing strength mixes. I used green wash and terra wash (degreaser) and started at 2% worked my way all the way up to an 8% mix. I sprayed one area several times with the 8% 3 times with 10 minute dwell periods in between. They got lighter but aren’t completely going away. It looks like rain hit the top of the wall and ran down the side, taking something that stained it with it. (the house walls are covered by eves so not a problem there) the entire property is only 2 years old. Pics attached. Any idea how to remove it?

Can you take a picture of the top of the ledge? You may wanna try gutter cleaner. Do it in a small area first may need to scrub it.

Easier to repaint

Thank you. Trying the gutter butter now. Also tried attack by sunrise environmental, barc and efflo from f9. Attack (caustic degreaser). The gutter butter worked the best!


It’s tinted material unfortunately

@Seandz I’m glad it worked for you