I did a fondant bow on top of buttercream icing cake, and the bow changed color after a few hours, it was mmf made at home, do I need to add something extra? to make the color stay?

I don't remember where I read it, but somewhere on here (the internet) it states that gumpaste/fondant will lighten as it drys. Add a little more color when you are mixing it, probably just slightly darker then what you actually want it. Hope this helps!

it works the other way too, some colours darken. i think wilton colours have the most problems with fading, and you need to make sure you keep the fondant out of the light as well.
xx

What color was the bow? Some colors are notorious for fading. Purple is one of the worst offenders. The red in it will fade in the light and you get left with a horrid corpse blue-gray color.

If it's just lighter though this is normal. The moisture evaporates from the surface and the color gets less vivid... like when you put a rock in water... you can see tons of detail and the color is rich, but when you let it dry off the color fades.

the bow was purple yes!! and the color did fade a little, so I guess I will try adding a little extra color, also I kept the cake on a closed container, could it be that the moisture left inside made it worst? should I just leave it opened in a dark place?
thanks everyone for your tips!

I suggest getting some high quality powdered food colors. They don't have the same fading issues that the gel colors have.