The red slate is a slate type bird with a rusty tint to the body, somewhat barred wing feathers with a few random black spots and reddish tan tail with a blue band, finished off with a creme colored tip.
The genotype is (b b Dd) bronze based with a single dominant slate gene. The red gene is not involved here, the reddish coloration coming through the blue is actually only the bronze color expressing. Bronze Slate or Blue Bronze would be much more accurate names.
They do not breed true: Three results should occur - Red Slate, Lilac and Bronze. The latter two will breed true.