Treatments/Masks to keep colored hair glossy?

I'm naturally blonde, but I dye my hair brown and the color seems to take a beating pretty quickly because the water in my area is so hard. My hair is in pretty good condition for being color treated, but about a month after getting colored the vibrancy just dies and it starts looking a little sad /emoticons/[email protected] 2x" width="20" height="20" />

I've never had luck with homemade masks, so can anyone recommend a good moderately priced mask or treatment I can buy online? 

I would definitely recommend getting a showerhead filter if you don't have one already.  Mine was like $60 from Lowe's and it has a filter which needs replaced every 6 months.  But, it's so worth it because our water is so hard it was damaging my skin as well as my hair.

I use Matrix Prizms Translucent Color Gloss to give shine every few weeks.  I just Googled it and it looks like they may no longer make it in the bottles I've used (I have a stock of three at all times, lol, they were black bottles) and now they are in white and purple bottles instead.
 

Bahaha, I DID buy a showerhead filter a few months ago and I've just been too lazy to instal it! Maybe it's time. I'll do a little search for that gloss too! Thanks!

I've also used John Frieda Brunette glaze stuff, it works too and I know that is easy to find in stores/online.  I hope the showerhead helps!!!