Cleaning a cola stain

Cleaning a cola stain

I recently purchased a white futon. There is a cola stain on the mattress. I used oxyclean on it and it basically disappeared. I thought the stain was gone, turned over the mattress and found that it had gone through the mattress to the other side. I used the oxyclean again on it, but it ran to the other side again. Does anyone have any advice to get the stain out completely?
spring yard pics

spring yard pics

Where did the summer go?

Where did the summer go?

Seedlings question, as well as a few other questions

Seedlings question, as well as a few other questions

I do love to make sugar cookies

I do love to make sugar cookies

My 3 African Violets

My 3 African Violets

Sharing my garden, ID help, and a weeding question

Sharing my garden, ID help, and a weeding question