| Value | Meaning |
|---|---|
| Win1X0 | 256 color max |
| Win2X4 + Win2xBitmapHeader.sizeof | 256 color max |
| Win3X4 + Win3xBitmapHeader.sizeof | 24M color, no alpha channel |
| WinNT4 + Win3xBitmapHeader.sizeof + WinNTBitmapHeaderExt.sizeof | 24M color, no alpha channel |
| Win4X4 + Win3xBitmapHeader.sizeof + Win4xBitmapHeaderExt.sizeof | Alpha channel enabled |
Mostly used during construction of new instances and version changing.