If you're hellbent on down streaming stucco you could do it 10 times and still wouldn't come clean. It looks like the streaks are darker because you pulled the top layer of funk off. Still got 67 layers to go if you're downstreaming.
We x-jet all stucco and dryvit. It still use to take 3 or more passes until @Clean1 told us to pull the proportioner out of the x-jet. And it took 2 passes to get here what you see below. That's almost a 50/50 or 60/40 mix. You're probably getting 12:1 or 15:1 out of your injector. If you don't have an x-jet buy one and tell them you'll be back next week or fall in love with your pump sprayer.