If you are using a colored mattress cover, the color may rub off on the mattress especially when you spilled liquid on the cover. This is why it is important to wash your covers first so some of the loose dye particles can be washed off.
Step 1: If your mattress has a white color, you can always try using bleach or hydrogen peroxide. These substances remove any discoloration from white fabrics. You can try mixing half a cup of hydrogen peroxide with one cup of water and pour it in a spray bottle. Spray it on the affected area and wait for about an hour for the dye to either fade away or resurface so you can easily clean it.
Step 2: Another tried and tested method is to use OxiClean. Purchase OxiClean from the grocery store and dissolve it in warm water. Get clean cloth and dip it in the mixture. Wring out some of the excess water and press the cloth on the stained area of the mattress. Leave the solution there to dry for a few minutes.
Step 3: You can also use hydrogen peroxide plus salt. This trick works well with red stains from blood so it should work well with blue stains too. Put a few drops of hydrogen peroxide on the stained area and immediately sprinkle table salt. Leave it there for a few minutes. You will begin to notice that the salt has absorbed the blue dye. You can slowly remove salt from the mattress. Rub damp cloth on the area affected to wash it off and then vacuum it.
Step 4: You can use vinegar and baking soda too. Both these cleaning ingredients have natural bleaching properties. Mix one part vinegar with one part of water and then spray it on the area affected. Let it sit there for 30 minutes. Afterwards, fill up spray bottle with water and spray it again on the affected area to wash off vinegar smell. Now sprinkle baking soda. This will help remove any lingering color or smell.
This is how you get rid of blue dye stains from your mattress. You can also use these to any other stains such as blood stains or pet stains. A clean mattress is always one that can improve your sleep experience. So try these cleaning steps right away and see a huge difference in how your mattress looks!