Look for the Bile supplements (there are 3). While there is no colored pictures, there is a lot of information contained and only rarely do I ever have to look up something else (in an Osprey or Funcken work).
Here is the link to the series at On Military Mattes: -
18260 Biles, William S. drawings by Darrell Capshaw UNIFORMS OF THE SEVEN YEARS WAR:Volume #1 Prussia, England, Hanover, Hesse-Cassel, BrunswickUniform detail, Flags, Standards, organization forInfantry, Cavalry and Artillery. B/w line drawingsbiblio, index.1 vol, 64 pgs 1997 HOPEWELL, OMM PUBLISHING
NEW-softcover
$15.00
..see our SEVEN YEARS WAR page for more books on this subject
1-18270 Biles, William S. drawings by Darrell Capshaw UNIFORMS OF THE SEVEN YEARS WAR:Volume #2 France, Austria, Bavaria, Saxony and Wurttenberg.Uniform detail, Flags, Standards, organization forInfantry, Cavalry and Artillery. B/w line drawingsbiblio, index.1 vol, 51 pgs 1997 HOPEWELL, OMM PUBLISHING
NEW-softcover
$15.00
..see our SEVEN YEARS WAR page for more books on this subject
1-18280 Biles, William S. drawings by Darrell Capshaw UNIFORMS OF THE SEVEN YEARS WAR:Volume #3 The Reicharmee(German States), Russia & PalatinateUniform detail, Flags, Standards, organization forInfantry, Cavalry and Artillery. B/w line drawingsbiblio, index.1 vol, 58 pgs 1997 HOPEWELL, OMM PUBLISHING
NEW-softcover
$15.00
..see our SEVEN YEARS WAR page for more books on this subject
Hope this helps
ERik