Create a collection of solid hatched areas using BHATCH, selecting custom RGB colours.
Create another BHATCH area to use one of the already used custom colours, but the BHATCH colour selector only has "select colour" as an option in its list of possibilities. So you have recreate colour again with possible error in specification.
If you allow the BHATCH to complete without specifying the custom colour - just allow any colour as OK, then select the hatched region > Properties, the Colour selector in Properties lists all the used custom colours as a available for selection.
Niggle: the BHATCH colour selector needs to use the same list as the Properties selector to save the potential errors in colour setting.
Create another BHATCH area to use one of the already used custom colours, but the BHATCH colour selector only has "select colour" as an option in its list of possibilities. So you have recreate colour again with possible error in specification.
If you allow the BHATCH to complete without specifying the custom colour - just allow any colour as OK, then select the hatched region > Properties, the Colour selector in Properties lists all the used custom colours as a available for selection.
Niggle: the BHATCH colour selector needs to use the same list as the Properties selector to save the potential errors in colour setting.