Suggestions for blindfold exercises I can now name the color of any square. Does anyone have suggestions for  some other visualization exercises I can do to improve my blindfold chess?
A friend of mine (and a stronger player) suggested one exercise which has helped me in developing my visualization skills.

Take a game, any game and read the first two moves of both sides (ie total four plies), visualize the position now on board, then make these moves on board, see if your visualized position was right.

Read the next two moves and visualize the current position then make the moves on board and check if you got it right.

Go through the entire game in these steps of two moves.

once you are fairly comfortable,  try in steps of three moves, Gradually increase the number of moves.

I am doing this for about 8 months now and now I can visualize boards over ~10-12 moves.

Already I play blindfold chess in lichess.org, by making the site speak out opponents move and I entering move through the keyboard. (Even though I look at the board once in ~10 moves)