Imperial German Cavalry for Return of the Tripods. These are the colors I happen to have on hand and others may work just as well. This scheme uses block colors with no real shading so it has sufficient contrast at a 15mm scale.
Prime in white and then paint the saddle blanket Caledor Sky
Paint the uniform Field Blue
Heavy drybrush the uniform with Fenrisian Grey
Paint the gas mask, straps, and pouches of the soldier and the gas mask on the horse Sandstorm
Paint the horse Doombull Brown
Paint the saddle straps, and the horse’s mane, tail, and hooves Corvus Black Paint the soldier’s boots and dot his eyes.
Paint the lance, rifle, and holster a lighter shade of brown with Mournfang Brown
Paint the explosive lance tip in Khorne Red
Paint the hands in Cadian Fleshtone and wash with Flesh Wash
Give the horses white socks with Bold Titanium White and paint the stirrups in Leadbelcher washed with Dark Tone
Paint the gas mask filters in Eshin Grey
Paint the base to match your basing material Warboss Green