Running a macro in the "close"state

Running a macro in the "close"state

I have spreadsheet in the iframe, which is updated with external data, I managed to find and apply the number color macro for values below 0 to be red and valued above zero to be green. However, the macro does not execute when external data updates. How do I correct this? Current result after a while the value turns positive but remains red and vice versa.

thank you for your help