Comparison of 0.3mm layers w/o fan (left) with to 0.2mm layers w/fan (right). Something curious: Slic3r barely included any infill for the 0.2mm version, even though I told it to have 15%.
are the color differences as dramatic as it seems in the photos?
Yes, it’s due to the 45% infill on the first model and essentially 0% infill on the second. It’s translucent enough that the black mousepad is causing the bluer coloration of the second model.