Once your breast milk supply increases, by the fifth or sixth day, your baby's urine shouldn't be concentrated, and it should no longer contain brick dust. (verywellfamily.com)
You may notice a pinky orangy color resembling brick dust in the baby's urine (see a photo here). (cindyandjana.com)
-- If brick dust or pseudomenses doesn't seem to fit with what you are seeing, particularly if your baby seems unwell. (cindyandjana.com)