Coloring agent and coloring method for theme facade road surface

The invention relates to a coloring agent for a theme facade road surface and a coloring method using the coloring agent. The pH of the coloring agent is less than or equal to 6.5. The coloring agentcomprises: an acid, a metal salt, a weak base, starch ether or cellulose ether, and water. The coloring method comprises: brushing or spraying the coloring agent to the entire surface of a facade, a floor, a wall, a rockery or a GRC component; applying the coloring agent repeatedly until the color depth is appropriate; as needed, swinging and splashing the coloring agent to local areas that need to be deepened by uadopting a brush to dip the coloring agent, and rendering a whole mottled effect; and sealing with varnish after drying. According to the invention, the starch ether or the celluloseether is added to the coloring agent, so that the water volatilization speed of the coloring agent solution is reduced when the coloring agent is applied to coloring of the theme facade road surface,the coloring reaction time in a wet state is prolonged, the penetration depth of the coloring agent is promoted, different color textures can be achieved and the durability is long.