Specialty Gardening: A how-to for making concrete pots inexpensively., 1 by ah_hoya

ah_hoya wrote:
I only use oxide dry pigment designed for use in concrete.
I have a Blue, Yellow, 2 Greens, 2 Reds, Black, White, and a whole bunch of Browns.
Mixing colors is always a surprise. Yellow and Red will not make Orange but mud brown instead.
But Blue and Green does do a nice attractive Blue/Green.
Also changing your admixes, or aggregates can radically change the color.
Also different sealers give different results, most darken and brighten the colors but not all.
Paste waxes can also be used to bring up the color.
If you want to cheat you can also apply a slurry of just Portland, white glue or admix, and pigment with a brush to save money. I generally use blue in layers of a 1/4 inch or less because blue pigment is very expensive.

Every new batch is an adventure. :)

I dry dozens of samples but also just wing it.
I mix my dry batches in 3 gallon buckets, then mix a sample in a small 2 inch square thin tile which I hot glue to the lid. But as time goes by I tend to add more color, more sand, more glass, etc, until what's left in the bucket is usually a surprise. For this particular pot I was only sure what the red and yellow would look like, the rest were a surprise.

If you are only making one or two pieces I recommend you mix a sample and let it dry for about 4-6 days so you won't be disapointed by your colors.

TIP: 3 or 5 gallon buckets with tight lids can be found free at many food businesses. Grocery stores that sell bulk foods generally have tons of them.
The three gallon size is nice because you can add all your dusty dry ingredients, put on the lid, and shake the bucket to mix them avoiding all the dangerous dust.