AnyShape hide-color not properly recognised in BSP

[SergeNL]

BSP 'remembers' the wrong color for transparancy.

In BSP Skinmaker I check "Skin Any Shape".
In Skinmaker this works properly: every area in main.bmp that matches the color of the upper right pixel is greyed out. (Ready to be transparant in BSP)
I save the skin in Skinmaker. (Menu Bar > File > Save)

But BSP itself keeps choosing the wrong transparancy color. I once chose a color blue for tansparancy, but when I change the color of the top-left pixel, BSP keeps hiding all blue area's.
I can fill half of main.bmp with red, including that pixel, but BSP still hides the area's that once were blue..

Doesn't matter if I restart BSP, or re-click the skin in the preferences window.

Is Tizio still around? :-)

NOTE: BSP is still a great player, but the available skins are not attractive or user-friendly at all. I am making a new one. Tizio's Skinmaker is really a great invention, but needs an update.