I did go through this. I did print about a 100 little circles of different blues in RGB, CMYK, and even Pantone.
I know what color I want - I want Pantone Uncoated 3115U, 3125U, and possibly 3105U, or 3135U. The only color I can match is 3135U, but it is really pretty dark to go with red.
When I tried printing after setting my Publisher doc to Pantone colors, the colors did not much the Pantone colors at all. I just thought maybe if I got people's codes I can try entering them for more trial and error. So so so tired!