1) Since a half-sister from the father's side did not share the mother's milk from her half-brother from her father's side is it permissible according to Shariah law and the Qur'an that they can marry legally?2) Since green with all it's grades is the Islamic color, why don't the sheikhs in the Gulf states and the Saudi's and Iran ask the women to give up the devil's color (black); any other color specially in those hot countries will be more convenient?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

As for the Hijaab, it should be thick, long, wide, plain without decoration, not transparent nor tight, and all colors are permitted.

As for your word that the black color is a devilish color, it has no legal evidence, since the scholars legalize black color for both men and women as mentioned in Al-Aadaab Ash-Shar'iyyah by Ibn Muflih . Also, the Prophet wore a black turban.

As for the Prophetic Hadeeth that reads: “the black dog is a devil”, it may mean:

1- The devil may appear in the form of a black dog.

2- The black dog is the devil of dogs, since all genera have their own devils; i.e., those who rebel and disobey. Ibn Al-Qayyim mentioned this idea, but this does not constitute evidence that the devil is black.

Finally, the inquirer is not permitted to marry the said female since she is his sister in lineage and she is one of the prohibited females to him as Allah Says (what means): {Forbidden to you (for marriage) are: your mothers, your daughters, your sisters, your father's sisters, your mother's sisters, your brother's daughters, your sister's daughters,...} [Quran 4:23]

Then, the case you mentioned concerning non-suckling between you has no effect on being a sister in lineage.

Allah knows best.