Actually, the build order will be 100 red, 100 black, 100 silver, but that has nothing to do with when they are released. They will already have 150 cars built by Oct. 1st, assuming they stay on schedule. Therefore, you could get your black car just as quick as the red cars, assuming you have one of the first 50 black cars built. So, even though a lot of cars will be finished well before Oct. 1, none will be released that day or possibly later.
I got the above info when I was at CAAP recently. Also, they will be built in batches of 30, not 40, after the first 300 cars.