I've checked this with apitrace, and it uses a 16x16 texture RGBA8, where the left half is 0xFFFFFFFF and the right half is 0x77777777.
0x77 is the default color of a surface in OpenSWE1R after locking a surface through IDirectDrawSurface4::Lock (set using memset). The game probably expects a different surface type or surface size when modifying that surface. It's also possible that the surface should have been set to a specific color before.
It's also possible that this is related to texture blending: the texture might simply be ignored when drawing.
I've checked this with apitrace, and it uses a 16x16 texture RGBA8, where the left half is 0xFFFFFFFF and the right half is 0x77777777.
0x77 is the default color of a surface in OpenSWE1R after locking a surface through
IDirectDrawSurface4::Lock(set usingmemset). The game probably expects a different surface type or surface size when modifying that surface. It's also possible that the surface should have been set to a specific color before.It's also possible that this is related to texture blending: the texture might simply be ignored when drawing.