Food coloring stain?

Blue food coloring stain on driveway. I have degrees sat for 10 minutes and then surface clean the area. Didn’t take it out. Sprayed straight bleach on it although a long shot, nothing happened. Who has experience with this and who knows what I can do to get this out?

Not being a smart guy, but did you try scrubbing it with a brush?

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I wet down the surface, applied f9 degreaser mixed with leftover purple power. Sat for 10, scrubbed in with a brush, sat for another 10. Pressure washed with surface cleaner at 3,000 psi. Lightened a bit. Rinsed it all, applied straight 10%, dwell for 5, nothing, use a 15 degree wand tip and pretty much went at it, got like 50% of it out, and then rinsed and post treated with 5% SH. It lightened alittle but no give. I’m Going back later to check it when it’s

I’ll let the pro PW answer your question as I am not a PW. I am just curious if it was food coloring or food dye. IF it was dye then I would say mineral spirits, dye is dye for the most part. I am thinking if you lightened it up, the rest will wear off with foot traffic, weather, and sunlight.

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Hot water might help?

Let’s hope! I didn’t set high expectations and she already wrote me the check for cleaning. I just want to see if I can lighten it up more.

Strong post treat 10% SH left to bake and dry . I believe that did the trick! Lessons learned ? Dye is pretty hard to remove. SH post treat left to dry is what made the stain disappear. When wet it was definitely still noticeable when I left. Customer is happy.


Just a thought: You may want to let the customer know that anytime that driveway gets wet the stain may show up again since you can see deeper into the concrete. It may not but if you give them a heads up it may prevent a disappointing phone call later down the road.

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I did, I told her “the concrete is like a crystal ball, when it’s dry you don’t see it but when wet you can see deep into the concrete”
Took that from someone else on here haha . Worked well !


Good deal. Always CYA.

I know that Thiourea Dioxide is used in other industry’s to remove dye but have no experience with it. I would love to hear @CaCO3Girl opinion on this.

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@MuscleMyHustle have no experience using this item. However, the SDS I found says it can spontaneously combust, so it isn’t something I’d like on MY truck. Having said that, I’m glad the stain issue seems to have been resolved. My suggestion was going to be sodium thiosulfate. Hospitals use it to remove iodine and blood stains from sheets (it’s part of the washing machine cleaning) it’s fairly inert, and bonus…it’s one of the the few things that will actually neutralize SH. I wouldn’t mind having some of that on my truck :-). You know, if I actually had a truck, which I don’t lol!