I need to put 4 burgundy/wine colored skinny diagonal stripes on all sides of a four tier wedding cake. What medium should I use? It was suggested that I use gumpaste and let it dry so I tried to color it with burgundy gel color it's too purplish. Tried adding some red and still purplish not really wine colored. Any suggestions?

I made a really good wine colour recently using Wilton burgundy and a bit of Wilton rose. You do need to use quite a bit of colour to get a deep shade, of course. I didn't think it turned out 'purpley', but you could try adding just a very SMALL amount of brown to it, which might give the colour you're after (I would test just a small piece of fondant/gumpaste first before going ahead and adding brown to the whole lot.)

I like Coral3's suggestions. One thing to remember though is that dark colors sometimes take a while to deepen. Wait 24 hours after you mix a batch and see what it looks like the next day. Also, gum paste's colors tend to dry lighter. I had to make a navy blue disc so I used gum paste that I had colored dark blue and then painted over it the next day with navy blue gel color (mixed with a little vodka to thin). It came out the perfect color.