I wasn't sure what you were talking about in your first post. What do you mean by a "nested" query -- can you elaborate??? Is there SQL that you have from some other system that is an example of a "nested query"?? Is this something being done within the context of EG's filter and query tasks or is this being done within the context of the BI Platform and stored processes? More info, please.
About the color formatting from your original question -- yes, you can change the color of report output conditionally, but it depends on what procedure you are using to create your output. For example, with PROC PRINT, PROC REPORT and PROC TABULATE, it is possible to perform conditional formatting.
In Web Report Studio, it is possible to generate a report using conditional formatting...
But again, without more information or context, it is hard to figure out where to direct you.