Gentlemen , When WW1 began some officers wear plain collar patches on the collar of the 1907 1910 Fielduniform . General Staff officers ,carmine plain patches, Medical officers ,dark blue plain patches piped red , Juridical officers ,light blue piped red and Paymasters officers ,dark blue piped white . finally Veterinarians wear plain crimson patches . and crimson piping of the SBs . but never i noticed about Infantry or field or foot artillery wearing plain collar patches with 1907 1910 field uniform . probably the Painter embellished the uniform of his client , and not all the Artists know necessary much about uniforms