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, sallallahu ‘alayhi wa sallam, is His slave and Messenger.
It has been authentically reported on the authority of Ibn ‘Abbaas, may Allah be pleased with him, that the Prophet, sallallahu ‘alayhi wa sallam, said, "On the night of my Ascent to Heaven, I saw Moosa (Moses), who was a tall, brown man..." [Al-Bukhari and Muslim]
The word used in the hadeeth to describe Moosa's color is 'Aadam'. Al-Haafith Ibn Hajar commented on the hadeeth, saying, "The intended meaning here is to describe Moosa's color as Adamah, which is a color between white and dark."
This confirms the first description that you mentioned in the question, that he was of light brown complexion. We could not find any statement of the scholars that he was dark-skinned.
Allah knows best.