I want to start with hello because I'm new to this site
I have a few questions I'm making my sons 2nd birthday cake for his party on saturday (2 it's gonna be hot wheels (:
Okay so when should I make the fondant? The colors I need are blue yellow black and red. I'm gonna make the cakes the night before and assemble the tiers (not stack tho since I have to cover with fondant) but I heard to get black you need to let it sit atleast over night to achieve a good black. So I also have to make decorations so when should I do those the morning of?

Thanks for any help )

I assume you are making marshmellow fondant? I would make it the day before at the latest...Friday morning. Marshmellow fondant does not go bad if you make it ahead of time. Make it even earlier if you don't want to cram everything into 1 or 2 days. If you are just talking about coloring already made fondant, you can do that as far ahead of time as you want. Yes, colors do darken a bit when left to sit for a while.

There is no need to leave everything until the last minute. It would be fine to make your fondant 3-4 days beforehand. As for the decorations, if they are fondant or gumpaste decorations you can start doing then a week early so they set etc.

Many people suggest leaving a fondant covered cake overnight to set before stacking/tiering, and before adding decorations, so perhaps you should reconsider when you are baking? But that also depends on the cake type. Light airy sponge cakes don't have a real long keeping time so you would need to leave the baking to the last minute, but many cakes are moist and a little (or a lot!) dense and so baking can be brought forward.

Sorry for not adding more information
I'm making box cake mixes and I an making marshmallow fondant and the decorations I'm making are flames and letters so I heard to make them when needed so they wouldn't dry out so they can form tithe cake also when I make the fondant do I have to put it in fridge our can I just leave it out wrapped in saran wrap in a air tight container till needed ?

(sorry for typos I'm on my phone)