How to make er icing bright?

I am making er icing for a cake but i want to make the icing BRIGHT. Just adding a few drops of food colouring makes the icing a vague boring pastel colour. So obvious way to do this is to add more drops of food colouring but I find too much of it makes the icing taste weird and gross. I've thrown out mive batches of icing before because I've tried to add lots of colouring to make it bright and it ended up tasting so grim. Any suggestions much appreciated. Thank you!