It looks like the conversion from step to svg is at fault. The svg has not translated the colors and has translated everything to polylines. I have only done a step conversion once, and I did the conversion manually from the step image like this (except here I started from your svg using Inkscape.) because I couldn’t find a way to convert from step to svg that preserves the colors (there may however be one that I don’t know about, I know almost nothing about step!)
First I copied in a text item in the correct OCRA font and changed the font size to match the font-size in the step image
Then deleted the “no” created in polylines and moved the text in to its place. Then I created a rectangle (necessary to be able to set the fill color) and a circle to replace the rectangle and circles in the image.
Then I moved the rectangle till the top left edge matches the rectangle made by the polylines then deleted the polylines in the rectangle (all 4 of them)
and stretched the rectangle (via the bottom right scale handle) to be the same size as the polyline rectangle.
Now I can change the fill color of the rectangle to put the color back in the rectangle like this (I also needed to move the rectangle up in the svg drawing order so the circles still show in the fill)
here I used a fill of blue rather than the tan of the original, but you get the idea. Unfortunately you need to do this for all the elements in the step image unless you can find a way to get the conversion to an svg to do the translation for you. In this case I created one circle but didn’t move it in to the blue rectangle.
edit: Here is a copy of my changed svg for comparison