Yeah, I know all about these headaches. I've been running all over Seattle and no one has even come close to matching the spa yellow (I was trying to do a body kit on my 98' targa) because they are all morons.
The problem really is not in the materials; the problem is in the clear coat, the labor, and the amount of time it takes to do it.
No one wants to touch the car because they know damn right well it would take days for them to get the color right; and for a few hundred bucks it is just not worth it for them to get involved.
However, I can reccomend one person on this planet that I know 100% can match the paint on this car; but he is all the way back in Pennsylvania. So, I have shipped him the part and he is going to ship it back. I trust him because he has been painting fire trucks since he was 5 years old and I have seen him do perfect matches every time on every one of my cars (including a metallic yellow on my 3000GT VR4 that he said was the hardest color to match hands down)
Don't buy into it- it is possible to match paint 100% it is only a question of hiring the right talent to make it happen.