Hi. I am making an electric guitar that's metallic sage green and white. How do I make this color in buttercream if I don't have an airbrush? Also, do you have any suggestions as to how to make the strings, knobs, electric plug in area (I don't know what this stuff is called lol) look realistic? I was asked to use buttercream, but SOME fondant would be ok. I'm making the tuners out of pretzels sticks with one end covered in fondant/gumpaste. Thanks! I love all the great tips and ideas I have gotten here!
I'm going to try to post a pic of the guitar. Ok...that didn't work bc my pic is too big I think.

Color your buttercream sage...(I cover my cake with regular buttercream then harden it in the fridge and then add my highly colored buttercream at the last so the whole thing isn't colored frosting).

After applying your colored frosting, put it in the refrigerator to harden, ( I prefer this to just letting it crust...gives a firmer surface), then you can do a couple of things to get the metallic look. You can dust it dry with pearl or luster dust...use a big soft brush...or you can mix the dust with lemon extract or vodka and paint it on. The lemon or vodka evaporates fairly quickly so you are not melting your buttercream. Using the extract or vodka will probably give you a more metallic look...but practice first to get the feel of it. Good luck!

Thanks, Carmijok! Should I use green luster or pearl dust? Which is better? Also, will vanilla extract or another extract work since I don't have lemon extract? Or rum or tequila? I don't want to buy vodka or lemon extract just for this!
What colors (I have wilton) do I mix to get sage green? Thanks so much for your help!!

Using Rum didnt work for me. It has a high sugar content and left everything I painted with it very sticky....but this was me painting on fondant.

You can buy really cheap vodka...or even the small bottles. You're going to need a lot more than you think you will so be prepared to go get either the extract or the liquor. I have not used vanilla, but to me that's more expensive--plus it's brown and would add color to your dust--same issue with Rum or Tequilla if it's not clear.

I buy the cheapest brand lemon extract (make sure it's clear) because I think the lemon evaporates faster. You can also use Everclear which has a higher alcohol content than vodka and I assume would evaporate faster as well. I haven't used that yet, but I haven't been to the liquor store in a while.

I think if I were just going for a metallic look I might try just the pearl luster dust. The green will add a green color to your sage and it may or may not look right. You might think of sprinkling some disco dust over it too to really give it a glittery sparkle...if you want that kind of sparkle that is.

The color 'sage' can vary in range from greener versions to bluer versions. I would start off with Americolor gel color Avocado and depending on the color I was matching either add a tiny touch of black or perhaps navy blue. And I mean TINY touch...like the tip of a toothpick. Sometimes the Avocado alone makes a good sage color.

Others here may have better suggestions...this is what I would do.
Hope it helps!

Thanks so much for the responses! I'm going to try once again to upload a pic!
Carmijok, is an airplane size bottle of vodka big enough for a cake that feeds about 12-15?