Planetary filters

Hello everyone, I'm new here and new to owning a telescope. I have got given a Celestron Astromaster 90eq mak for Christmas. It seems to be really cool, especially for the moon as I have got given a lunar filter as well. Now, the weather here has been awful, always cloudy. But recently, the conditions have been very good, the only problem is that it is new moon at the moment here (I think tonight the moon will be slightly visible). So I decided to try it out on planets like Mars and Jupiter as they were up, even though I knew it isn't the best telescope for planetary observations. The view was surprisingly alright, the planets were pretty clear. I started by observing an augmented version of what I saw in the sky, like a bigger white dot. But then zoomed in and I saw what I believe to have been the planet. The thing is the planet was black and white (it kinda looked like what can be seen when one looks under a microscope). I have done some research and there are some planetary filters. I just don't know which one to get? I'm scared to buy one and not be fit for my Celestron Astromaster 90eq mak telescope. Thank you everyone!