I have created three new sets of icons for Chief Architect's .PLAN, .LAYOUT, .CALIB, and .CALIBZ file formats. I think these will look especially good with Windows 8. (I don't have Win8).
To change file-type icons in Windows7 and Windows8 you will need a third-party application (I recommend the free program FileTypesMan).
The attached thumbnail shows what the icons look like in the various Windows 7 views. My favorite is the Full Color Hoizontal ones.
Chief Icons 2014.zip