I feel your pain. I am not "well that will do" kind of gal. But here is the problem. Cobalt blue only means something to you, and it isn't very much more specific than "blue". But if you really want a very specific color (and you are allowed to want what you want), and you have to communicate with other people (because computer/camera/software is not accurate/specific enough. You have to refer to a "standard" of what the definition of Cobalt blue is. (have I lost you/bored you? In the print world the standard is the pantone color chart. (John Deere want this green not that green in their ads, paint etc and you better not print an off shade like forest green).
Now we don't all have Pantone color charts, but we do/can have Kona and/or Bella Solid color charts. By we, I mean you can buy one, and most LQS have on e. If you say "Do you have any fabric that matches Kona "Cutsy Blue #236 or Bella Solid "Heavenly blue #117", that LQS owner can refer to her chart and walk her store and/or refer to her website; Moda #24567 of the Country charm collection matches the color you have referred to. And wal la you have a match.
If you don't need to be THAT specific, then, heck, trust your computer and go for it. Or hop in the car and take a rode trip. Good Luck in your quest. I know when I want a solid, I am like you, I want what I want and not something "close to it"