Ok. I hate to say this but here is where you went wrong. When creating an identity , start with spot colors (PANTONE) first!!!!! The PMS is a proprietary and CALIBRATED blend of inks that produce a certain hue. You cant, even on a calibrated monitor, create CYMK or RBG ( or any other color mode) and convert to Pantone. Eyeballing it, tho tedious, unprofessional and inaccurate... may be your only option. If the brand hasn't been created yet this really wont have much consequence, otherwise you have your work cut out for you for color matching a set standard. Best of luck.