Should i wear a white t-shirt while washing cars?

so i'm 13 and my school is doinga carwash. i don't think any guys will be there though only girls i guess. and well the uniform is whit shirts and black pants. i have black pants and i don't want to get in trouble for not wearing uniform plus i don't have any black shirts either. and of cours i would wear an undershirt for the shirt lol. but would it still show through if i get water on myself?