Hello,

M-x describe-variable RET whitespace-style RET

says:

[snip]

   indentation::tab     8 or more SPACEs at beginning of line are
                        visualized via faces.
                        It has effect only if ‘face’ (see above)
                        is present in ‘whitespace-style’.

   indentation::space   TABs at beginning of line are visualized via
                        faces.
                        It has effect only if ‘face’ (see above)
                        is present in ‘whitespace-style’.

[snip]

That looks backward to me. Attached is a patch that fixes it.

-David