Some reds are as simple as formulating for roots and ends and too keep the color vivid.
Other reds need a bit more help. This one started light green with compromised ends. I used a very gentle formula to lift that slightly, then filled the blonde with a light warm red.
More red had to be added, as well as violet while isolating the brightness to keep it where we set it. The final result is dimensional and shiny after a reconstruction treatment.