I've been enjoying the discussion about colorbursts & brushos. While I might not rush to buy, they are both interesting. Brushos reminds me of the dry color we used to make scene paints for flats & scrims. You'd mix the powdered pigments with sized water to make the actual paints.
Sarah. with the brushos pots, I'd bet you would have a problem with the humidity if you used a piece of saran wrap as an inner seal under the perforated lid. And... if you have old spice jars with a shaker style top & lid you could transfer them to those. Better still? Write the mfr & tell them to fix their packaging! Who knows, they might listen!