Ignore the white look to the edges on the orange - I tried sanding the ridges out.
Stair case patterns on sloped or radiused surfaces are normal and inherent to the process, the step heights get smaller while the amount of steps increase with reduced layer heights but there still will be steps.
They will not effect the Marple runs function and you will have to decide on print time vs. “better appearance” with the layer height settings.
You could use the Variable Layer Height option from the toolbar.
I wouldn’t bother if you have already printed it though.
You have the sphere problem in reverse 
Means the same fix applies.
Try this:
Use a variable layer height for the model.
Try do stay within reason and try to be smart.
Like using a 0.1mm layer height as the default for the model so you can combine a few infill layers to save print time.
For those steps in the model you decrease the layer height in those sections.
E.g.: Instead of 0.1mm you go down to 0.08 or 0.06 if your calibration and filament allows for it.
Check your current staircase…
A lower layer height will create more steps on the surface, thinner steps.
If the model was printed with 0.2mm layers than printing those sections in 0.08mm will make a huge difference, both for the surface and the print time I am afraid.
If this is not enough to satisfy your surface quality needs you can always cheat…
Keep in mind though that you always have the PREVIEW in the slicer to check things!
Whatever steps you see there will be in the printed model.
The lower the layer height of those steps the better the outcome.
After that comes paint…
Tape off what does not need paint or do the entire model to get a uniform look.
Apply THIN coats, preferably using airbrush, spray can or such.
Apply just enough paint so the surface if evenly covered.
Means you do several of these thin coats to avoid the paint from running or drooling…
Now use fine sandpaper to sand off the paint and expose those layer lines again - JUST those fine lines poking through the paint…
Do this evenly please.
Use a DIFFERENT colour and repeat.
Like light grey and white…
Free tip: Have two water sprayers at hand, one filled with water and one drop of dishwashing liquid, the other with methylated spirit.
Sanding wet means the sandpaper won’t clog up and you get a smoother surface.
Using the alcohol after wiping the model dry and then wiping it again speeds up the drying time as the alcohol bonds with the remaining water on the model.
Still use enough time and airflow to make sure no trapped water will mess up the next paint coat…
Why use two colours?
You will get to the point (quicker than you think) where the sanding exposes both colours.
You get a nice marble effect - no pun intended.
That is because with every round of sanding you also remove a tiny bit of the layer edge, with that the paint up that level.
Once the sanding only exposes ONE colour and a tiny filament line your surface is smooth like baby bum…
Then you just apply the top coat of the colour you like and Bob’s your aunty.
Thanks folks, that’s what I figured but wanted to make sure I wasn’t missing anything. I don’t remember seeing the pattern on pics and vids of other marble mazes so I thought I’d ask.
