Clarify default value for useowncolors

specs/udmf_zdoom.txt

@@ -203,21 +203,21 @@ Note: All <bool> fields default to false unless mentioned otherwise.
 	  nogradient_top = <bool>;	    // disables color gradient on upper tier. (Hardware rendering only.)
 	  flipgradient_top = <bool>;    // flips gradient colors on upper tier. (Hardware rendering only.)
 	  clampgradient_top = <bool>;   // clamps gradient on upper tier to actual bounds (default is the entire front sector height, hardware rendering only.)
-	  useowncolors_top = <bool>;    // Set to 1 to use the colors set in the sidedef. Default is using the colors from the owning sector.
+	  useowncolors_top = <bool>;    // Set to 1 to use the colors set in the sidedef. Default is true if uppercolor or lowercolor are set, otherwise it's false
 	  uppercolor_top = <int>;       // Material color of the top of the upper tier.
 	  lowercolor_top = <int>;       // Material color of the bottom of the upper tier. (Hardware rendering only.)
 
 	  nogradient_mid = <bool>;	    // disables color gradient on middle tier. (Hardware rendering only.)
 	  flipgradient_mid = <bool>;    // flips gradient colors on middle tier. (Hardware rendering only.)
 	  clampgradient_mid = <bool>;   // clamps gradient on middle tier to actual bounds (default is the entire front sector height, hardware rendering only.)
-	  useowncolors_mid = <bool>;    // Set to 1 to use the colors set in the sidedef. Default is using the colors from the owning sector.
+	  useowncolors_mid = <bool>;    // Set to 1 to use the colors set in the sidedef. Default is true if uppercolor or lowercolor are set, otherwise it's false
 	  uppercolor_mid = <int>;       // Material color of the top of the middle tier.
 	  lowercolor_mid = <int>;       // Material color of the bottom of the middle tier. (Hardware rendering only.)
 
 	  nogradient_bottom = <bool>;   // disables color gradient on lower tier. (Hardware rendering only.)
 	  flipgradient_bottom = <bool>; // flips gradient colors on lower tier. (Hardware rendering only.)
 	  clampgradient_bottom = <bool>;// clamps gradient on lower tier to actual bounds (default is the entire front sector height, hardware rendering only.)
-	  useowncolors_bottom = <bool>; // Set to 1 to use the colors set in the sidedef. Default is using the colors from the owning sector.
+	  useowncolors_bottom = <bool>; // Set to 1 to use the colors set in the sidedef. Default is true if uppercolor or lowercolor are set, otherwise it's false
 	  uppercolor_bottom = <int>;    // Material color of the top of the lower tier.
 	  lowercolor_bottom = <int>;    // Material color of the bottom of the lower tier. (Hardware rendering only.)