Hair dye question/advice

I have very dark brown hair but my beautician said it should take dye bc it’s “virgin hair”??? So I’m being adventurous and gonna be dying the underneath of if (if it doesn’t work it’s not the end of the world). Looking to do a red or purple and was wondering if anyone has box dye brand recommendations or things I should know (besides it may not show up) when dying darker hair since this is my first time! Thanks :)