As long as you are comfortable and can maintain that position without discomfort I think you should be fine.
Black is not bad, if you're doing this at night, you may be perceiving what is past your eyelids. What I like to do is imagine a screen. It'll look like a movie screen or an empty picture frame or a white board. Now a days it's turned into a white stage, it's different for everybody and most use what works best for them. The least complicated at first the better because that way you don't have to feel like you're struggling to keep up this idea.
Hey maybe for you you're looking at a television!

It's black when it's off right?
Just turn it on to plain white 'picture.' 
Except this time you have a remote control in your hand and all you have to do is ask your controller to give you a clear image and just flip through the channels till you find the right station

lol that sounds like fun I might just try that ha ha ha

hmm come to think of it in some readings I have LOL it's just wasn't off

silly me.
Or you can imagine it like a laptop or your iphone (lol if you have one, everyone but me seems to have one these days

). grab the image and zoom in if you have to, or brighten the screen. Have fun with it and do what works bests for you. In the beginning however, for whatever this screen will be, imagine that it has a white frame that has a connection to God above and the Earth below. It'll help keep things positive and channel anything that needs to be grounded to the earth so that it can be transmuted back into light for later.

What you may want to consider trying is creating your meditative home so to speak. Imagine a place where you feel
peaceful and secure that has good lighting and a nice comfy seat. You can make it as grand or as simple as you like. This will be your go to place. It could be a beach, a garden, a rooftop, the Taj Mahal hey even your bedroom as long as it's free from unnecessary distractions. From there when you take a seat rest for a moment be there and enjoy the peacefulness of it. Take a walk around and get to know your space from top to bottom. Once you have that you can use it as a jump off to more advance techniques. Then if you feel like it look at your screen and see what you receive. Or you can program it to send something like a goal. I gave Malick a couple tips on visualizations in "Abilities..." check there if you can (so i don't have to repost it cuz boy I can talk

)
Above all, enjoy it!