Nope. The technology used in the Mixer "brush" is not available in the Painter 8 brush variants.
You can mix colors with a lot of Painter's default variants and/or with brush variants you adjust to have blending characteristics.
Experiment with the Brush Creator > Stroke Designer > Well section's Resat and Bleed sliders, adjusting the Resat slider so it's to the left and the Bleed slider is to the right of the Resat slider setting, until you get the desired result.
Please do not PM me with Painter questions. Instead, post them here where everyone can benefit from them. Thanks!