When selecting a color table to attach to the master file it does not appear to be attached or affect the reference file's colors. Also, when creating a Drawing View the color of the objects in the Master file are not the same as the model in the reference attachment.
Steps to Accomplish
Below is the workflow that will allow the reference file to use the same color table as the master file.
1. Choose File > Settings > User > Preferences > Reference and enable the Use Color Table option.
If disabled, OpenBuildings Designer ignores any color table attached to a reference file and displays its elements using the active design file's color table. This speeds up loading design files with references attached but may change the colors of elements in the reference attachments. The default is on, but a change is not effective until OpenBuildings Designer is restarted.
2. We can override the Use Color Table user preference (File > Settings > User > Preferences) by creating and setting the configuration variable MS_REFCOLORTABLE.
MS_REFCOLORTABLE = 1, OpenBuildings Designer always uses the reference's color table.
MS_REFCOLORTABLE = # any value other than 1, OpenBuildings Designer never uses the reference's color table.
If MS_REFCOLORTABLE is not defined OpenBuildings Designer uses the user preference mentioned above to determine whether or not to use the reference's color table.
Also see: Match the color table of elements between sheet and design models