The filter intake/output are green because they are eheim pipes that go with the eheim filter, I didnt choose the colour, thats the way the come! The internal is large, but thats standard with Juwel tanks, I was going to remove it (as I do with all juwel internals) but will leave it running for a while, it actually doesnt take up that much space, just the corner, which most fish wont be interested in anyway.