Matron, MOH, And Maids

Hi,

I would like to know if the matron and MOHs should have a different dress from the bridesmaids?
My problem is that i may only have 4 girls. One is the Matron, two is the MOH, and one possible two bridesmaids.
Also My dress is mostly rum pink and ivory. It has been very hard to find colors to match. I found this dress at davidsbridal that is celadon and have a rum pink sash. I thought about putting the Matron and MOHs in all celadon but then that would leave one possibley two girls in the sash dress. Are there any other colors that would work with my colors and not clash? the rum pink is like a champagne with a hint of pink. It really do not look pink at all. Please help all advice is greatly appreciated. Thank you so much for your time and hope to hear from you soon.

Tracey