Hi guys.  Sorry that it has taken me so long to get to the Ombre Wedding Cake post.  I'd say I've been super busy but it seems like I'm always really busy, so that's not a good excuse. 

This was an extremely fun cake to make.  It was a lot of trial and error because, once again, I had no guide as to how I was to do it.  I simply looked for tips online and had to copy what I saw.  I did do a practice cake first because I wanted to be sure of the colors.  I learned from the practice cake that I wanted to go very very very light at the top and very very very dark at the bottom.  That helped emphasize the color changes. 
Okay, so this entry is going to be a bit wordy as I try to describe what I did.  We didn't want the tiers ridiculously high but we also wanted at least 5 layers, so we opted for a 3/4 inch layer.   This would put the tiers at about four and a half inches high.  

I started by making up a lot of batter.  With this particular cake I opted to use cake mixes because I wanted a reliable cake where I could focus solely on moisture and color.  I love a scratch cake, but I really needed something that I could count on.  The white cake mix works great.  Just make sure that you don't over bake it.  Your toothpick should come out clean and your sides of the cake should pull away from the pan after you take it out of the oven.  If your sides have pulled away from the pan before you take it out, chances are you're over baking it.  I used three mixes and divided them up between 5 bowels.    
Then I started coloring the layers.  I only put a hint of color in the first one (the metal bowel).  Then I progressively added color to each bowel.  I started off light on the theory that I could always go darker if need be, but couldn't lighten up if I made a mistake.  
When it was all done, this is what I had.  One thing that I did notice is that depending on the color, the top tier needed differing amounts of dye.  With this teal cake I only colored it slightly (as you can see) but when it was baked, it came almost completely white.  It looked as though I didn't color it at all.  I'd seen pictures online where the top layer is white and didn't feel like it matched the cake color progression, so I tossed that layer (well, put it in my freezer to eat later) and made another one (I actually ended up remaking two layers).  However, with the fuchsia colored cake, I only put a slight bit of dye in and it came out looking great.  So a lot of this really is trial and error.    
Here is a picture of the green batter...
And here are the teal layers, ready to assemble.  With this cake we made 10 inch tier, two eight inch tiers, and a small anniversary tier.
So after all the cakes were baked, I started assembling them (taking care to make sure the colors were all in the right order, obviously).
After assembling the cake, I did a light crumb coat.  I wasn't concerned about the cake showing through because the flowers would cover up anything that the crumb layer let through.
I then did the same with the green tier...
...and the fuchsia tier....
After giving each of the cakes a light crumb coat, I set to work piping the roses.  I used the 'i am baker' tutorial for the roses: http://iambaker.net/rose-cake-tutorial/  Basically, you use a 1M star tip and just start piping circles on the cake.  If you don't like how they are looking, just scrape them off and start again.
I piped roses all around the base of the cake...
Once the sides were done I did the top.  Then I filled in the gaps with swirls of frosting, trying to follow the curves of the roses, so they would blend.
This is what the cakes looked like at the venue  She had the smaller tiers up on the pedestals and the larger tier flat on the table.
The bride made these beautiful peacock feather butterflies.  
Everyone was really impressed with the cakes, but of course, the real surprise came when they cut into them and the guests got to see all of the colors.  It turned out beautifully and was a wonderful night!