Good Is... - Final Pieces

When I have come to print my final pieces, the blue hasn't come out consistently as all together there has been three different printers used to print them out. I'm not really happy about this, but I have left it too late to get them printed so I don't have the time to go again and get everything done from on.

I am guessing that this is down to the colour that I have used being a mix of CMYK instead of specifically choosing a spot colour from the pantone swatches. I did this because I thought with me only going to be using digital ways of printing it wouldn't necessarily matter at this level, but obviously when it would come to commercial printing I would have specified the colour as I found one that was almost identical, and the only difference is the shade is the slightest touch darker. The pantone number for this is 299C.