When you set a temperature for a print, your printer TRIES to stay near that but ends up overshooting it and undershooting it in a sine wave pattern. Your temperature sensor (thermocouple for the M200) tells the computer to apply or reduce heat accordingly.
I’m guessing this material you are printing with is very temperature sensitive (or too moist) and/or your thermocouple (temperature sensor) is bad or loose.
Try the same thing with other materials and make sure to print directly in the middle of the temperature range the material prints at. It looks like you might be printing at the highest part of the range here, and your temperature is oscillating higher, which burns the filament a bit as it is coming out, causing the color change.
P.S. With the Zortrax M200: in the Z-Suite software you can click “Print” -> “Advanced Settings” -> “External Materials” (in the dropdown menu that says “Zortrax Materials” by default) … after you do this, you’ll be able to select a template (that is probably wrong) for whatever material you want to print with. You can change the temperature you print at here.
Also, Zortrax customer service will help you even if you didn’t purchase the printer from a retailer. I got mine from craigslist and they still helped me with my problems.
Another option to consider is Z-Temp and the related Z-LCD which displays the temperature as you are printing.
Link to a related post of someone with the same problem.