After all discussion on TrueColor... is really true?
https://knowledge.autodesk.com/it/search-result/caas/CloudHelp/cloudhelp/2016/ITA/AutoCAD-ActiveX/files/GUID-A186333C-4857-4DFD-97EC-CDF75523299B-htm.htmlColor Property
Specifies the color of an object or layer.
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This property is obsolete and will be removed in a future version. When using this property, colors can be set and read as numeric index values ranging from 0 to 256. Constants are provided for the standard seven colors, as well as for the BYBLOCK and BYLAYER designations.
If you use acByBlock, AutoCAD draws new objects in the default color (white or black, depending on your configuration) until they are grouped into the block. When the block is inserted in the drawing, the objects in the block inherit the current setting of the color property.
If you use acByLayer, new objects assume the color of the layer upon which they are drawn. The value acByLayer is not valid for a Layer object.