I think I'm going to change my son's shirt
What's the reason for that? Is the shirt ugly?
I simply don't like that shirt and I want to change it
How old is your son?  If he's old enough to choose his own clothes, you should let him wear any shirt he wants to. Having some autonomy is important for kids.
Nope, I don't care what you say.
Why don't you ask to see what shirt your son likes between the two shirt options? Kids that have autonomy are nice because you don't have to bother with them as much, which means less stress for you. I think you will love it with all the extra time you save.