You had the gutters cleaned in spring. The leaves are gone, the downspouts run clear, and the outside still looks like something spilled down it. That is not a bad cleanout. Those are two different jobs.
The stripes are not dirt off the roof
Rain sheets over the gutter lip and carries airborne grime, pollen, and roof runoff onto the front face, where it bonds to the finish. It builds in vertical bands because that is exactly where water goes over the edge, which is why the pattern is so even and so obviously not splashing. Every roofline on the block has them. You only notice once yours is darker than the house behind it.
Cleaning the inside does nothing for them
A leaf cleanout is about function: getting water moving again before it backs up under the shingles. Brightening is about the face people see from the street. Different tools, different chemistry, and one has never fixed the other. This is worth knowing before you book, because plenty of people pay for a cleanout every year and stay annoyed that the house still looks streaked.
Pressure does not fix it either
Gutter aluminum is thin. Enough pressure to shift a bonded stripe will dent the face, drive water behind the fascia, or strip the factory finish and leave a chalky patch that looks worse than what you started with. Same lesson as the siding and the roof: if it is bonded or alive, force is the wrong tool.
What works is dwell time, not force
A detergent that breaks the bond, left long enough to do the work, then a gentle rinse. Outside faces only. It takes longer than blasting and it is the only version that leaves the gutter looking new instead of looking attacked. Done alongside a house wash it is barely an extra stop, which is usually the sensible way to book it.
One thing we do not do
We do not do leaf cleanouts. If the gutters are packed and overflowing, that is a different trade and you want someone who does it properly. What we do is the outside: the streaks, the stains, and the part of the gutter your neighbors actually see.
Not sure which one you need? Send a photo of the worst run and we will tell you honestly, even when the answer is that you need the other guy.