GM used the same primer on all colored cars, there was no special primer for different colored cars.
As long as the original paint is intact, you do not even need a primer. The advantage about using a primer is that it might help to hide the old color easier, but you will have to buy the primer AND the paint that you like. Is the existing paint latex? Is the new paint latex? Is there any bare drywall? Unless there is something that we don't know, I would just buy enough paint to paint the wall 2 coats. If you want to prime it, you can have the primer tinted a little to get you closer to the color that you have chosen, but it will be more trouble and work than is necessary.
use the factory coolant that came with the car in otherwords don't change the color of it if your unsure what was original if unsure of the original go with the green.
White primer is for use as a primer for lighter colors and the grey is best used as and undercoat for darker colors(blacks, dark blues, dark green etc..). A darker top color requires more coats with lighter color primer.
Primer is almost always the exciting color of light gray, so if you're painting with a light color, you should stick with the gray. Primer could theoretically come in any color, but gray is what you'll nearly always see used. Sometimes a shop will use a darker primer such as red for certain darker colors of paint so that they won't have to use as many coats of paint to cover the usual gray primer.
Since it is an oceanic blue color, I'd suggest that you use a primer that is tinted to at least 3/4 of the top coat. This should give enough coverage over the old color to allow you to recoat with only one additional coat. If the primer is not available in that dark of a color, then a gray primer will suffice.
Yes, you can because brown primer isn't that dark of a color.
Orange. Why are you using a primer? If the walls are already painted, just apply 2 coats of the paint that you want to use. If you use primer, have the paint store tint the primer toward the orange color that you have chosen.
I am looking for the same color.
If it's the standard light gray primer it should be alright.
YELLOW
what is color scheme?
black