I made my icing last night, and iced all 8 layers of a fake 4 foot wedding cake.
Now, my icing colour has changed .... gotten darker.
Should be dark cream, but it reminds me of a mustard.
Anything I can do ... besides starting over.
Cake is due tomorrow, Sunday.

maybe stick it in the sun. But I think the best thing would be to start over.

would it work if I took all the icing off, lightened it, than but it back on. It has crusted over already, but maybe if a mix it up again it will be ok?

icing always gets darker as it sits. the best thing to do is add white icing to it!!

so taking all the icing off and mixing it with white icing would help?
I would only add a small amount of the coloured icing to the white, right?

yes...it always works for me.
take a little off and add some white and see if that's the color your looking for...remember it will get darker as it sits.

Remember to start with white and then add small amounts of your dark ivory color until you get the color you want, keep the color a few shades lighter as it will darken again. If you start with your batch of ivory and try to add white you may end up with a ton of colored icing that you don't need. Also you can use what is called brite white to lighten dark shades.