Good advice above.
Since you are talking about colors that “ look good “ on you, I think of that as “ face colors”, so, tops ( or dresses) , toppers , scarves. So my thoughts are mostly about those items. As opposed to if one is thinking, my outfits are boring, I want to add more interest , more complexity but keep base the same- dabbling purses, jewelry, shoes.
I agree that a good way is to look for something that’s about exactly what you wear in what I guess are neutrals, so the item is smack in your comfort zone but color is different. I love those blues you showed and actually they are rather “ quiet “, and mix well with neutrals. So you could get a little more granular about which colors are your best, visually, and see which of those are most closely aligned with your regulars, or of course, just your favorite color !
Probably you don’t want to spend loads
on an experiment , so I do applaud the thrifting. However if it’s not the same quality as what you usually wear, or doesn’t fit other needs for fit, fabric, care requirements, you might end up disliking it for those reasons.
I have been adding pieces in a few of my colors that are less mainstream, and I do have to be careful about “ color goggles “, Ooh, look at this color! , and not being picky enough about fit or style or quality something. Unless it’s very intentional, such as I’m going to get this T shirt on sale just to see if this color really works. But even then, it still is a waste if that T shirt is wonky.
I’m sometimes tempted to go in the other direction— wear clothes that aren’t my best colors - many classic neutrals are not good face colors for me-so it is easier to mix and match. Especially for travel capsules.
I’m also influenced by “ closet candy” photos. As you know, a lot of blogs and photos of “ capsule wardrobes” and lovely organized closets feature a soothing, gently graded color lineup of just a few neutral colors. So, visually it’s very soothing and also those types of posts seem to outnumber more realistic closets!
Anyway, you shouldn’t feel you have to make changes just because someone else likes how you look in something, but you can experiment on a small scale to see if you yourself have some real “ happy colors”, and you can do just an item or 2, or a small capsule , or something at- home like pj’s, robe, loungewear.