Review (5/5): Superior lasting colors!
I've used a few SFX colors and have never been disappointed!
• Cupcake Pink: love this color so much, but definitely needs a very pale base (closest to white blonde, and porous, as possible) or it'll turn a salmon/peach color.
• Atomic Pink: the absolute best hot pink! Deep, electric, and long lasting.
• Sonic Green: more blue-based than I originally realized, I loved the green-teal color. Perfect mix of green with a bit of blue and fades almost minty. It covered over orange bleached hair well.
• Blue Velvet: a gorgeous deep denim blue that starts out deceptively dark and begins to lighten after a few washes. Easily applied over orangey bleached hair.
These are direct, veggie-based dyes, so it does NO harm to leave in your hair long. The longer you leave it in, the more difficult it may be to remove later when you want to change colors, but it'll also ensure you don't need to touch it up for awhile. I easily went over a month on the above colors without needing to refresh.