Re-painting drywall after patching leaves tones

Question

I patched a few scrapes and small holes in the drywall, then got a can of color-matched paint in the hardware store (I took a sample with me, they color-matched it and prepared the paint). It is a white color anyways.

However after I applied a first coat, I clearly see that there is a difference in color tones on the wall - the new coat is "darker" then the original one. So I applied the 2nd coat at one part of the wall to see any changes - but I see no difference.

Was I supposed to apply a primer first? Isn't it late now to apply it and then re-paint?

Thanks.

Answer 1

Three things:

1. Yes, you were supposed to apply a primer.

   Fresh joint compound and drywall soak up paint like crazy. The primer serves to seal the joint compound and drywall and create a consistent surface. However, you've already painted - and the paint will do the same thing - just not as effectively and you'll probably need to do a third coat.

2. Paint takes time to cure and changes color as it does

   It takes about 30 days for paint to cure fully - and usually the color will deepen as it does - so after your 3rd coat let it set a week and see if it's starting to blend in.

3. Your paint may never match perfectly

   Paint age matters - and no matter how good the technology, 2 cans of paint are 2 cans of paint. Pro's who get multiple cans of paint at a time for a room will blend the 2 together before painting to ensure uniformity. Obviously it's too late for you to do that - your old paint was dry - but worst case if you really can't stand it after it's cured - just paint the one wall with a new coat. Having a whole wall be slightly off color won't stand out anywhere near as much as having a spot of paint off color.

Answer 2

The paint likely does not match perfectly, either in color or in amount of gloss. Those color matching machines can be hit or miss...

If it bothers you - paint the entire wall with the new paint and you’ll never notice the slight difference in color.

Answer 3

In addition to other comments: If your wall has a texture to it, orange peel texture spray can help to make it more seamless. Applying it is an art. A little goes a long way and you need to get the spray pattern right. Definitely practice on an old board first on a wall you don't care about like in a basement. Feathering the edges into the surrounding area will also help confuse the lines.

It's almost impossible in my experience to get it exact. I've gotten pretty close but at certain angles the glare will be different. If you really want perfect uniformity, you need to repaint the entire wall but that still won't work if the patch is perfectly smooth and the wall isn't.

Answer 4

Had a job that involved color matching plastic parts, vinyl, painted parts and rubber. surface texture was a large problem for matching, even tho samples submitted would match numerically within 5%. Material of which the parts were made caused significant difference. We used two brands of color match instrumentation plus a light booth where different lighting was available; in the end, while I made sure the color instrumentation matched the colors tested, I had three sets of human eyes view and sign off the samples that were deemed acceptable.