Inconsistent DLL linkage with cmake

Hey folks, so I tried installing this into my cmake project with the following lines:

add_subdirectory("./src/third_party/color_widgets")
target_include_directories(${TARGET_NAME} PRIVATE "./src/third_party/color_widgets/include")
target_link_libraries(${TARGET_NAME} ColorWidgets)

CMake runs fine, but when I try to run my application, I'm getting the error cannot open file 'ColorWidgets.lib', as well as many warnings like this:

Warning	C4273	'color_widgets::Swatch::setReadOnly': inconsistent dll linkage

Any ideas what could be going wrong?

Edited Jan 20, 2021 by Dante