Hi Victor,

to IIS.
I'm no expert but here's my thoughts.
Filters. I have a quite a few coloured and some moon and polarizing filters, but can't remember when I last used them. Some of the more specialised ones, e.g. for nebula, can enhance the viewing I believe, but never used one so far.
Colours. I'm afraid not, your eyes are not sensitive enough in low light to pick them up. The images you see are taken with a camera, which has much greater sensitivity. Colours can be seen in bright objects like stars and planets, but not in nebula and other diffuse objects.
For clusters and nebula, generally a low to mid power eyepiece with a reasonably wide field of view. Useable magnification is subject to variation according to conditions (atmospheric transparency, light pollution etc.) From my light polluted backyard with the 10" Dob, a 25m or 15mm is what I use for these objects.
Cheers
Bill