Each test use the first background-image first and then the second bacbkground-image.

transparent - blue

un-premultiplied
premultiplied
un-premultiplied
premultiplied
2

blue - transparent

un-premultiplied
premultiplied
un-premultiplied
premultiplied

transparent - yellow

un-premultiplied
premultiplied
un-premultiplied
premultiplied
2

yellow - trapsparent

un-premultiplied
premultiplied
un-premultiplied
premultiplied

trapsparent - green

un-premultiplied
premultiplied
un-premultiplied
premultiplied

green - trapsparent

un-premultiplied
premultiplied
un-premultiplied
premultiplied