Is it forbidden to wear pants, T-shirts, shirts, suits, or any other attire besides the jilbab? And must its length not exceed the ankles? And are there any disliked colors? And is it a condition that the garment be short, not exceeding the ankles, during prayer?

The basic principle concerning clothing is permissibility, and nothing is forbidden except what a specific text indicates to be so, such as silk for men and transparent clothes that reveal the awrah (private parts). The types of clothes mentioned in the question are not forbidden, and wearing a long shirt is not a condition, even though it was the Prophet’s (peace and blessings be upon him) most beloved garment. Exceptions to permissibility include tight clothes that define the awrah, especially during prayer, and colors are not disliked except what has been said about red for men. One must observe Islamic guidelines, such as men not imitating women, or Muslims not imitating disbelievers, and not wearing clothes of fame. As for isbal (lengthening a garment below the ankles), the preponderant opinion is that it is forbidden absolutely, whether in prayer or outside of it.