ugh!!! I just went back into my email to make sure I had the little boy's name spelled correctly, and I realized that my friend asked me to do "White icing, with multi-coloured balloons". I iced the cake sky blue

It's a cake for 40, and I normally charge $2.50/serving... what discount would you suggest?? I've Never made a mistake like this

If you have the time, do it over.

If not, I'd be prepared to offer her a 25% discount and see what she says. You may end up having to do more depending on how upset she is about this and how badly you want to make her happy. You will have to be penitent and apologize.

I wouldn't be so quick to start offering discounts for such a minor thing. I would just fess up to your mistake, apologize, and see what her reaction is. Maybe she'll say, "Oh, I love the sky blue, I would have never thought of that". or "Oh, I love it so much I didn't even notice", etc. Don't offer a discount unless she is upset, then I would ask her what would make her happy. Consider offering a discount on a future cake; that way you're at least guaranteed another order! If you'd said you opened your email and realized the kid's name was Stevie and you wrote happy birthday Chris than I would say a big discount is in order!

If she hasn't picked the cake up yet, I'd just see what her reaction is when she sees the cake. Most likely she'll love the colored background and it can be your use of 'artist license' instead of a mistake! If she comments negatively, then worry about a discount, or better yet - credit towards the next cake.