create single Colour Indicator Measure for global grading

Hello,

I have a couple of reports where I wish to create a single Colour Indicator Measure for global grading using images (red, amber and green circles).

The example below shows a table with file sizes. Each file is colour graded in the table but I would want to assign a global grading, currently just using text (see the "Green" above the "File Size KPI" measure, on the left).

I have already created another table with the list of icons and Image URLs.

My question is

Is there a way so that I can convert this text into showing an image. Or possibly both text and image for B/W printing of the report?

I found this post with what seems like a way of doing it but I am failing to understand the 3rd step explaining how to create a dynamic image.

This is the formula with the conditional statement driving the colour grading criteria.

File Size KPI = IF([MaxFile]>200,"Red",(IF([AvgFile]>150,"Amber","Green")))

Thank you

J