Yep, there is NO WAY a value line like Dimension is going to match good enough for "panel painting" (not blending). You couldn't even get a top of the line paint right off the mixing bank to pull that off with a metallic let alone a value line.
And "black" is not black at all as you have learned, there is no such thing as "Black" realistically, it is extremely dark blue, red or brown. So blending it out even solid black when painting something like a door is pretty much essential.
On most any color on a late model car there is going to be many "alternates" or "variants" as some paint companies call them. The auto manufacture builds these cars in factories all over right? Not only that but they are building that same model style and color for many months if not years, right? So they have to buy paint many times and sometimes even from different sources.
This being the fact, a Honda Prelude made in Jan 2005 and one made in Sept 2005 though they have the same color code on their information sticker in the door jamb are often going to be very different in color! The paint could even be a different brand! This is where these "alternates" come around. The paint manufacturer in the high end lines will have color chips for all these alternates found in a particular color code.They will often have five, six or even ten or twelve different alternate colors for a given code and year! These colors will often be VERY different from one an other.
These colors are all hand matched by color techs in the color lab at S-W, Dupont, Sikkens, PPG, etc. And they spend a LOT of money on these matches. To these manufacturers the color match IS their sale. If they have colors that match better than the other company it means HUNDREDS of millions of dollars in sales. Color IS the paint business more than anything else.
So, with the low end lines they don't spend ANY color time at all on them. They are often simply computer matched and are NOT designed for panel painting at all but more of an "overall" paint with no alternates what so ever.
To match that color properly you are going to need to blend into the fender and the quarter then clear over the entire area.
This isn't a big deal, you can mask the stuff off or remove it as we do at the shop. The bumpers and lights come off VERY easy as does the rocker moulding and you can pull all this stuff off,scuff it with a scuff pad (there are more to these steps but I am cutting to the chase), mask it and shoot it in not much longer than shooting the one door.
Study up on blending here on the net and you will pull it off without a hitch. You have about the easiest color there is to blend so that is in your favor.
Brian