I am about to do my first wedding cake for a friend and her dress is champagne so i was going to tint the icing as close as i could to the dress. Is there a trick to getting all the batches the same color? Or is it just an eyeball kind of thing. Thanks for any help!

Count the number of drops of color you put in the first batch and do the same for the remaining batches (assuming all batches are the same size). After each batch is tinted you could start mixing them together until all are the same color.

Try tinting the water you add to your buttercream. This will ensure every batch is the same color. I would suggest making a lot more water than you think you need.

Using the other suggestion you then put all the batches into one bowl and stir it up good

Those are some really great ideas. Just an FYI, I had to do a wedding cake the same color and I frosted two of the tiers the night before and the third and final tier the next morning. After I frosted the third one, I realized the other two that I had frosted the night before were definitely a lot darker. Okay maybe not a lot, but really really really noticeable to me and my friends. I freaked! By the time I had to deliver it to the wedding it was mildlly better but still noticeable to me. I'm a fondant girl and this was my first icing cake. Boy did I learn my lesson!