I hate when customers proof art on phones and I tell them in our statement we prefer proofing on a larger screen, we also give them the ink colors we will print, I've found people have missed misspell words proofing on there phone or missed a name they they might have left off, colors etc. Far as colors on monitors I can tell my wife to come look at something on my monitor and she swears it's a certain color until she sits down in front of the monitor and look, the angles standing up makes the colors look different.
get an IPS monitor. they have a much wider angle and thus more consistent color. Much, much better tech and only marginally more expensive these days.
pierre