What should I do to keep colors pure and streakless?

[TrevorDemented]

I have a problem when painting and keeping the brush clean so that the color is pure. I have been using acrylic and gouache.

For example, I'm painting mushrooms for practice. I paint the cap cadmium red first then I decide to paint the stalk of the mushroom cadmium yellow. But the yellow gets desaturated and looks like a muddy yellow or it has streaks of red.
I have water and a cloth to wipe my brush and I try not to over load the brush with paint.

What should I do to keep colors pure and streakless?

[Elwell]

1. Rinse your brush untill it's clean/ get more brushes.
2. Make sure you're not picking up wet paint from the canvas when you don't mean to. Fortunately, with acrylics this just means waiting a few minutes.

[Doomgriever]

3. make sure u post in the right section :) this is critiqe center