Soft Washing Paint Issues: The Risk of Organic Pigment Color Change
As a professional pressure washing company in Tallahassee, Florida, we help homeowners deal with the constant humidity that leads to annual algae, mildew, and other organic growth. A Soft Wash House Washing is the safest way to clean this… most of the time.
But one of the most serious soft washing paint issues we can encounter is a rare but disastrous organic paint color change.
The Culprit: Organic Pigments & Soft Wash Color Change
Our Soft Wash House Washing solution is industry-standard and designed to kill organic growth—algae, mildew, etc. The problem is that some rare paint formulas use organic pigments for their color.
Our algaecide (Sodium Hypochlorite) is a powerful tool, but it can’t tell the difference between the organic pigment in the paint and the organic algae on the paint. It attacks both, effectively “bleaching” or stripping the color straight out of the paint. This isn’t just a risk with soft washing; this paint can also be discolored by pesticides or household cleaners.
The “Magenta” Clue
In our experience, this organic paint issue is most common in formulas that use a Magenta dye to create the final color. The most common colors we see with this issue are dark and light blues. When our solution comes into contact with the paint, it turns the color to a fluorescent greenish color—we believe it may be inverting the magenta dye.
A Key Distinction: Organic Color Change vs. Oxidation “Damage”
It’s crucial to understand the difference between this rare pigment reaction and other common soft washing paint issues.
Organic Pigment Reaction (The Rare Issue): This is an instant chemical reaction. The color completely changes to something new (e.g., blue turns a fluorescent greenish color). This is not the fault of the contractor; it’s an unfortunate incompatibility.
Oxidation Removal (The Contractor Error): This is what happens when an untrained operator uses too much pressure or a solution that is too strong. This fades the paint by stripping off its chalky, oxidized top layer. It doesn’t change the color, but it leaves an uneven, blotchy, or streaked finish.
Where Does This Organic Paint Issue Come From?
This is extremely rare on whole-house siding. We might see it only once every other year. It’s slightly more common on exterior doors.
Here’s the key observation: We have never seen this issue on materials pre-painted by the manufacturer (like factory-finished vinyl siding, doors, or shutters).
This problem has only occurred on surfaces painted after installation, either by a homeowner or a painting contractor. This strongly suggests the issue is with specific aftermarket paint formulas—paint that is designed and sold for exterior use but is ultimately unsuitable for any humid climate.
NEW: How to Prevent This Problem Before You Paint
If you are planning to paint your home, you can prevent this headache.
Ask your painter: “Are you using any paint formulas that contain a magenta dye?”
Test it yourself first: Before committing to a color, get a small sample of the exact paint formula. Paint it on a test board and let it cure. Once it’s dry, apply a small amount of household bleach (which contains Sodium Hypochlorite) to the sample and see if the color reacts.
Check with the supplier: It is still a good idea to ask your paint supplier about this issue directly. While the person at the local paint desk may not know (this is a high-level corporate issue), some are aware and may be able to guide you to a formula that is known to be safe.
What Are Your Options If You Already Have This Paint?
This is the most frustrating part. If your home has this paint and is covered in algae, we have not found an effective, safe cleaning solution.
The paint manufacturers and the painting contractors who applied it often don’t want to take responsibility. This leaves you, the homeowner, with no clear path forward.
Our advice is to contact the paint company where the paint was purchased. The original buyer of the paint has more pull and a better chance of getting a response from the manufacturer than we do as a cleaning contractor.
The Takeaway: How to Hire a Pro & Prevent a Disaster
This entire situation highlights why the test spot is the single most important step a professional washing company can take. It’s the one thing that stands between a routine wash and an irreversible, costly disaster.
A true professional will always test first, even if it means telling you they can’t do the job.
Before you hire any company, ask them these two simple questions:
“Are you familiar with organic paint pigment issues?”
“Do you perform a test spot for this before you start cleaning?”
If they don’t know what you’re talking about, or say they don’t test, do not let them wash your house.
Further Resources
For other contractors or homeowners dealing with this specific, frustrating issue, there is an active online community run by an experienced contractor dedicated to this topic.
Since 2012, Nick Loomis of Hot Water Pressure Washing has been a trusted expert in Tallahassee's pressure washing industry. With over a decade of experience, he's passionate about two things: delivering incredible results for his customers and finding innovative solutions to do the job right.
