Thank You for the brush settings explanation, that helps! Does Photo's Paint Mixer Brush have any setting that would clean after each stroke? I think that might be the challenge I am having with it? Then I can control the amount of blending using the flow and mix settings. So the way I use the mixer-brush in photoshop is by setting the color/clean brush to a null color (basically cleans brush after each stroke) that way it becomes a blender for smoothing out or mixing colors together. RYB is a historical subtractive colour model based on red, yellow and blue as primary colours.

Model-selects a different colour model for use with the brush.

Clean Brush-removes the mixed colour currently on the brush, leaving a brush with no initial colour applied to it.

Auto Load Brush-when selected, each new stroke will automatically Load Brush as described above before pixels are applied to the page.

Load Brush-removes the mixed colour currently on the brush and replaces it with the Colour 1 swatch colour set on the Colour panel.

Type directly in the text box or drag the pop-up slider to set the value.

Strength-defines the extent to the smudging.Force pressure to control size-Click to control brush size with pressure if using a pressure-sensitive device.

More-click to display the Brushes dialog to access advanced brush settings.

Flow-how fast the brush effect is applied (1% is very slow, 100% is immediate).

Width-the brush (stroke) size in pixels.The following settings can be adjusted from the context toolbar: As you drag the Paint Mixer Brush across the page, the colour currently on the brush blends with the colour on the page, smudging and mixing them together. The Paint Mixer Brush is ideal for digitally simulating the mixing of wet paint applied to a canvas.

Ps blending brush