Chart Grid: change scale format (/1000), color of legend components, background color

I’m trying to improve a chart and have 3 problems left to solve:

  1. I changed the line colors but that doesn’t affect the color in the legend.
  2. The scale takes too much space for mobile devices. Instead of “3.000 W” I’d like it to be “3 kW”. Something like “axisLabel:
    formatter: {value}/1000” only gets an error.
  3. I know how to set the color of the mainspace but not of the borders surrounding it