how to reset iMac 2013 27" display

to factory settings.--any way to do that?

and am I the only noobie that finds dealing with apple support by phone, maddening, mostly only partially successful --?

and frankly, think that would be a good exercise for our Guantonomo bay clients to help them pass the time-
I have much better results on this forum. thank you for your help

i just looked at that.......

that is a lot more of reset than i had in mind. i am a noobie and wouldn't dare tackle that ---that is like killing a fly with a 12 gauge( at least for me) why arnt there some simple settings for this or are there....seems like their should be- but thank you for your trouble_

let me see if i can simplify this a bit

this may not be a problem at all.--I have restarted twice after the restarts (iMac 27" 2013) the colors have been obviously hosed up window border lines to faint to make out colors more vivid than should be --however both times after a while.(i am guessing 30 min to an hour or so ) seems to adjust to normal.???????---so i was/ and still am a bit perplexed) anyway until it get gets permanent i will do nothing. i do know how to re calibrate i think.so it maybe manageable. sorry to have bothered you. but, maybe this a sop for this model?? anyway all is apparently ok now---