Found: 1970-1980ish Private girl's school. MC's only friend dyes dress for dance, dye rubs off on her skin

1970-1980 (could be older) Girl at boarding or private US school attends dance w/ dyed dress/it rubs off/date from nearby all male private school tried to help get the dye off her skin in the restroom/school thinks they were up to illicit behaviour. Not Fog Comes on Little Pig Feet, or Is that you, Miss Blue? but same genre and time frame. Female French teacher propositions MC (minor subplot). Not sure if boarding school or just a well-locked down private school environment. Main character was mid-teen girl, not well off financially like her classmates, and her friend had to dye her school prom dress, and the dye sweated off on her skin. Teacher discovered her in restroom, with her male date from the nearby boy's school, trying to help her scrub off the dye from her skin and assumed they were breaking school frat rules. Also think one of the teachers was lesbian and tried to have a relationship with the main character who said no. She turned her down saying I think one of us lacks the proper accessories, echoing that teacher's snobbish policing of the students' clothing.

Taking a stab in the dark that this rings a bell with someone. Thanks.

Are you sure you are not mixing two books up? The scene with the botched dye job is definitely in Is that you, Miss Blue?, but the lesbian teacher is not, so this might be a different and 2nd book.

>2 Nooiniin: I could well be mixing them up, you're right. I was seven years old at the time I read this. Running to check Are You There, Miss Blue more carefully to see if that is it. Thank you.

Nooiniin, you are wonderful! It is that book. And I did mix up two books. Miss Blue has two women teachers having an affair but the section I recall with the MC being propositioned is not in this book. So somewhere around same timeframe I read a second boarding school book in a similar style. Thank you again for your help.

I think there was a scene in Harold Robbins' "Goodbye, Janette" or one of his novels.