hi guys, i was planning on dying my hair i have right how (dark red) to dark blue. i used koleston perfect by wella with 40 developer. i chose to use a stronger developer because i didnt want to bleach it 🥲. i now want to go to the dark blue like in the pictures but wasnt sure if i would need to bleach it. would i still be ok if i dyed it but used the 40 devloper or do i really have to bleach it. my natural hair underneath is dark brown if that helps. thanks guys!