Revert "[color] allow alpha to omitted when converting from strings"
Revert "[color] allow alpha to omitted when converting from strings"

This reverts commit eb8daac4b0726c1d9925bbbaeed7a8f39007da21.

The original commit was incorrect and pushed accidentally.

kerrickstaley/clutter-vala,heysion/clutter-clone,rkudiyarov/clutter_osx,jigpu/clutter,djdeath/clutter,djdeath/clutter-multithreaded,jigpu/clutter,Distrotech/clutter,heysion/clutter-clone,jigpu/clutter,djdeath/clutter-android,nobled/clutter,GNOME/clutter,jigpu/clutter,dlespiau/clutter,jigpu/clutter,djdeath/clutter,spatulasnout/clutter,djdeath/clutter-multithreaded,Distrotech/clutter,ebassi/clutter,djdeath/clutter-android,kerrickstaley/clutter-vala,djdeath/clutter-android,spatulasnout/clutter,kerrickstaley/clutter-vala,djdeath/clutter,djdeath/clutter,djdeath/clutter-android,collects/clutter,ebassi/clutter,nobled/clutter,collects/clutter,heysion/clutter-clone,nobled/clutter,djdeath/clutter,djdeath/clutter-multithreaded,Distrotech/clutter,collects/clutter,spatulasnout/clutter,rkudiyarov/clutter_osx,rkudiyarov/clutter_osx,dlespiau/clutter,djdeath/clutter-android,heysion/clutter-clone,GNOME/clutter,collects/clutter,ebassi/clutter,djdeath/clutter-multithreaded,collects/clutter,spatulasnout/clutter,GNOME/clutter,djdeath/clutter,GNOME/clutter,GNOME/clutter,Distrotech/clutter,Distrotech/clutter,heysion/clutter-clone,jigpu/clutter,ebassi/clutter,dlespiau/clutter,kerrickstaley/clutter-vala,Distrotech/clutter,rkudiyarov/clutter_osx,spatulasnout/clutter,ebassi/clutter