Pavlo, painting yellow, red whatever, on with a brush is no more difficult than with a A.B. I think you are using the wrong size and type of brush.
You should have no problem brushing on any colour, providing you....
Clean the plastic thoroughly with soapy water.
For large areas use as wide a flat headed brush as is practical.
Mix the paints really well. The yellow definitely hasn't been mixed enough.
Don't over thin your paints.
i would suggest the brush you used for the green was far too small and the wrong shape, use a large, flat headed brush.
You will need more than one, two or even three coats to get a uniform coverage, particularly trying to cover a darker colour. Don't be tempted to thicken your paints for subsequent coats.
I use Vallejo paints and usually leave my stuff covered and outside to dry for around 2 hours or so, then I can apply a second coat with no fear of the previous coat dragging.
I hope the above is of some help to you.
Ron