Definition of "regimentals"

As when two doves, or two wood-pigeons, or as when Strephon and Phyllis (for that comes nearest to the mark) are retired into some pleasant solitary grove, to enjoy the delightful conversation of Love, that bashful boy, who cannot speak in public, and is never a good companion to more than two at a time; here, while every object is serene, should hoarse thunder burst suddenly through the shattered clouds, and rumbling roll along the sky, the frightened maid starts from the mossy bank or verdant turf, the pale livery of death succeeds the red regimentals [i.e. blushes] in which Love had before drest her cheeks, fear shakes her whole frame, and her lover scarce supports her trembling tottering limbs.

1749, Henry Fielding, The History of Tom Jones, a Foundling, volumes (please specify |volume=I to VI), London: A[ndrew] Millar, […]