Hi, any chance of a posting a sample file for someone to check or at very least some screenshots.
There are quite a few things that affect rendering, for example, if you rendered using the Lightworks engine in v19 and are now using the RedSDK engine (didn't purchase the lightworks plug-in) things will look a bit different, drawings are easily affected by changes in Lights / luminance, is there a render scene environment selected is you 2017 deluxe or pro (deluxe doesn't have advanced render style).
Note - if you can post a file and it has any 'wrapped' materials for example a sphere with an image of the earth wrapped on it, you would need to include the image also.
A material Category is similar to a folder, think of it as being an organiser each category contains a specific set of materials, i.e. metals, woods, etc. You will also find a category of 'Active drawing' this is a temporary folder which TC uses to store materials for the current drawing (it didn't exist in v19), it keeps a separate list which is saved with the drawing, and it allows playing around with materials without affecting master TC materials,
Foreground wireframe - the non-renderable if ticked shows any 2D stuff in the 3D render for example text (though in a RedSDK render it will always be black), with Renderable ticked it shows the wireframe of any 3D objects in the render, for example it can render a realistic block of wood and include a black outlines along its edges.
Render style, is a big subject with lots of settings, it basically affects the quality of the render, but I'll have to leave that explanation to the likes of Darrel, Dean and Majo.