Probably, but it depends on the top and even where you live in my opinion. If you live in a place where undergarments are never shown, then you will call a lot of attention to yourself. Other places in the US it is more common to have bra straps and even bras more visible. However, even in places where it is common there is a line where it looks trashy.
Honestly, and this might be mean for me to say, when I picture a see through purple top at all it sounds trashy to me no matter what is under it. I have tops that are slightly transparent, one I wear a bra underneath, one I wear a camisole, but the style and color are not what I associate with trashy, one is black and one is a brown pattern. Either color could still be trashy depending on the shirt, don’t get me wrong.
What is the style of the top? Will you have cleavage showing? Is it short and your somach is showing? Are you wearing a very short skirt with it? As long as you are not trashy with the entire outfit it might be ok. I always say you can only be skimpy in one part of an outfit, more than one, and it looks trashy.
Also, something to keep in mind, boys do interpret these things in the most sexual way they can. My husband looks at women wearing thong underwear and imagines they walk around wanted to get fucked all the time. Sorry for the swear word, but have sex is not crude enough. Many girls think thong underwear is better because no underwear lines, but the truth is then you have a thong line. So even if the girl is a virgin and sex is far from her thinking, many of the boys looking at her are not thinking that.
@Imadethisupwithnoforethought I miss the 80’s. My hair did better with glue in it. Now it looks like a raggy flat mess all too often.