RE: Painting question - Orange

>Are there any suggestions for better coverage or a primer base color
>that would do a better job for a one coat layer of orane base?

Orange and Yellow are both difficult 

white base is best - if using low pigment hobby paints you will have
to air-brush it to get a good effect. Two light coats 

Otherwise get artist acrylics as they have a much higher pigment content
and cost of course.

You will still be lucky to get away with a single coat.

-= tim jones =-