Discus eating problems

Question
Hi, I am wondering what to do about one of my discus fish, (Tikka), as he/she will only eat red food. We have tried lots of stuff such as flake food, brineshrimp and ox heart. So far, we have had him/ her for about 4 weeks, and Tikka will only eat the red blood worm. Tikka will come up to the food at the feeding times but every time turn away as it is not red.
I was wondering if red food colouring is poisonus to fish, and if this is not an option, what I can do as the blood worm is quite expensive. The ox heart is cheaper so would it be possible to colour it?
Thanks
( the fish is also a super red melon, funnily enough!)

Answer
AJ,

I have included a website that I think you might like to read. It is best to feed them a variety of food to keep them healthy. I would continue to feed the other foods you have instead of only the blood worms. Do this for a few days so that the fish knows that it has to eat what you give them. They are just like us and know what they like but feeding them only one type of food is not good for them. I hope the website helps.

http://www.rockymountaindiscus.com/Discus_fish_food_recipe.htm