I found that the best way, for me, is ;-
Start a BLANK IDW
On the ribbon select "MANAGE"
Then "STYLES EDITOR"
This should something like the attached "Styles Manager.jpg"
Select "LAYERS" Attached as ."Layers.jpg"
Go to the layer that you want to look at or change the its settings
Highlight it in the LH pain that also highlights the same layer in the RH pain
Move to the selected layer in the RH pain and click on the the colored box for that layer, selector color you want form the drown-down "color.jpg"
Click on SAVE at the top of the Exit Style Manager (not active ,BLACK, in screen shots because I made no changes)
once again go to the STYLES EDITOR in section in the ribbon click "SAVE" click OK/YES in the popup that comes up
As form there on ALL you dim should be created in you new color
If this dose not work check you line settings in "TOOLS - DRAWING" tab
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Inventor 2025 Pro
HP Z420 workstation
Xeon 3.7Ghz CPU 8 Cores, 64 GB Ram
64bit (The Garbage known as) Windows 10 Pro
AMD FirePro V3900 (ATI FireGL) (1GB RAM)
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Ashington Northumberland (UK) ~ Home to the WORLD FAMOUS Pitman Painters Group