I am making a cake for St. Patricks Day, and I was hoping to get a few ideas. I am making a pot of gold and I would like to have a rainbow coming out. This isnt going to be a flat one, but a standing up pot of gold with a rainbow coming out. I was thinking of a few ideas. Rice Krispies covered in different color fondant or dye the marshmallows different colors for the Rice Krispies or Fruity Pebbles (like rice krispies treat style). ANY OTHER IDEAS?! If you suggest the any of the Rice Krispies ideas, is there a link or website or your personal experience that will help me keep the rainbow in place or what density I should make the Rice Krispies. Thank you all.

You and I must be visualizing very different effects. You want a big, fat rainbow?

I'd make it out of flooded royal icing so it would be flat and lightweight.

I guess we are! Very funny. I want a FAT rainbow because my pot is thick and fat. This isnt a delicate project at all. I am concerned with how well the rice krispy treats will stand up.

I would make it out of gum paste and let it dry so it is rock hard. I find RCT a bit prone to sagging.

Oh, well in that case, I need more information.

What 3D shape are you thinking of? Round? Like a tube? Or four-sided?

Will the end of the rainbow be up in the air? Or curve down and end at the cake board?

I'm still having trouble wrapping my head around a 3D rainbow. Where will the colors start? And end?

I agree with RCT sagging, and if I do go that route, then I would add more marsh. Gum paste isnt a bad idea at all, I will chalk that up as a possibility.

DianeLM, wow you are a Forum SuperStar! I have never had to post on here because people like you contribute a lot of information, and I really appreciate it. I was thinking four sided for sure. However round can be a possibility and seems kinda cooler. The rainbow will end, and will not be in the air. In fact, I am going to cook some mm and make it landing in the clouds. The whole rainbow will be colored from start to end. I plan on baking RCTs then cutting 14 inch long lanes being 1 ½ in width, and then covering it in fondant, then put four lanes it in the middle of my pot and bending it. Kinda get a better picture? Because I can tell you are a lot more experienced than I am, so it may sound odd the way I am explaining it. This is my plan, but I have never done it so I am seeking suggestions. Also do you have any ideas on a big cake board?

Okey dokey... I think I'm getting the general idea.

I wouldn't use RK treats for this. I think they'd be too heavy.

Also, if you want to make RK treats firmer, use LESS marshmallow, not more. More marshmallow just makes them mushier and more prone to drooping.

I would still go with gumpaste or preferably, fondant with tylose mixed in. I would also build the rainbow on an internal structure, such as several wires twisted together or soft copper tubing.

I think I'd cover the support with white fondant+tylose to form a base, let that dry, then cover the base with strips of colored fondant. Or paint the color on.

I suppose you could cover your internal support with RK treats, too. Then you should cover with a coat of buttercream or royal icing to smooth out the bumps. Then, cover with strips of colored fondant.

I'm just throwing a bunch of thoughts out there... I'm working on two cakes right now myself, therefore there aren't enough brain cells available to plan out your cake.