I am making a Pumpkin cake for Birthday  and I am not sure how much fondant I will need to use to cover this type of project. Also would it be better to mix my own orange or purchase fondant already tinted orange? I don't have an airbrush yet sadly so I'm relying on a base color of fondant mainly.  Anyone have any ideas or experience they could share?  I'm using two bunt pan cakes to get the pumpkin shape. Then I hope to crumb coat and cover in fondant. I'm not in a time sensitive position for this project  its for birthday on Halloween.  Any help is greatly appreciated thanks! 

I can't help you with how much you will need, but I can tell you it is easier to get pre-tinted fondant.

I wish I could remember how much I used many, many yrs ago when I made something similar but alas......it's been far tooooo many yrs.  Just know that kneading color into that much fondant will take lots of time.  Not sure if buying already purchased orange would be expensive but you have to decide that.   Many times those pre colored fondants are too bold so consider using say 1/2 or 2/3 orange mixed w/white.  And to add debth maybe get some powdered color to brush over here & there once the cake is covered.

I would tint it orange, and come in with a dark petal dust to shade the contours.  This is what I did for a pumpkin cake made a few years ago. But I used round pans and carved them into the pumpkin shape, iced with chocolate ganache which set up nice and firm, and made covering with MMF a very easy process.