If you are needing only shine (a semi-permanent fix) is exactly what I would add. You can find and order clear gloss under most hair color companies through Amazon. I would choose this route instead of re-coloring your hair with original formula because it limits over processing and/or deepening your color. Another option is using a semi-permanent gloss/glaze in same tone as your current color, this option is highly preferred if red pigments bleed (red pigments are hardest to keep).
Chlorine Dulled My 12 Day Old Haircolor. What Will Bring My Hair’s Shine Back?