Great decals, batch to batch color matching has issues

This is my second batch of these decals for my website. They've worked really well in high stress automotive applications (on rally cars where the elements are thrown at them mercilessly). They still look good after a year of UV and elements. The only reason I give an 'Ok' instead of a great on this batch is that the colors didn't match up on the second batch. The yellow wasn't quite the same. Not the end of the world, but people are picky about what they stick on their cars and if they're going to have more than one they want them to match. Other than that they're totally top notch!