[TOMT] [Painting] [1700s-1800s]

Need help finding painting of a ginger haired woman looking into water/a lake reflecting and there is a rainbow over her face. The background is light blue behind her and rendered in a realistic style almost like evelyn de morgan's work but not her. It could also be allegorical/mythological but bc I can't remember the title I'm stumped. Truly do not know the time period bc terrible about stuff like that but I would place it before 20th century for sure.