Is the prohibition of wearing red related only to dyeing with safflower, what is the ruling on rolling up sleeves in prayer, and is it prohibited to put safflower in food?

Tashmir (tucking up clothes) in prayer is mildly disliked (karaha tanzih). It is possible that what the Prophet, peace and blessings be upon him, did was either coincidental or to show permissibility. It is authentically reported that the Prophet, peace and blessings be upon him, wore red. Scholars have explained the "red robe" (al-hulla al-hamra') as a garment striped with red lines along with other colors. Wearing mixed red is permissible, while pure red is disliked. As for adding safflower (usfur) to food and mixing it, there is no harm in it, because the default rule for things is permissibility unless there is a prohibition.