iphone 4 has yellowish tint i just noticed out of warranty home button not responsive as much

hello, i just wanted to start off by saying that my phone is out of warranty and wanted to know if apple would consider replacing my phone out of warranty for a hardware flaw.

so i have been having my phone for more than a year and a half and i just noticed that my phone had a yellowish tint, i compared it to my friends phones and they had a nice clear white crisp screen while mine looked very weird with the yellow tint. also the home button isn't as responsive as before and it gets annoying pressing the button twice just to get to the homescreen and i don't want to end up using the assistive touch. My question is if their is any way to fix tis problem? or if apple would replace it with a replacement phone since im out of warranty? please help!