Conditional Formatting

Good Morning Excel Community,

I am in the process of creating a model with specific formatting to allow external users to follow and understand the file.

Can you help develop this "conditional formatting" to help me achieve my task instead of doing things manually?

1. I would like to be able to select a selective cell range and if there is a "hardcoded" input then that cell range will be highlighted in the color of my choice -- light yellow
2. For all standard text  such as descriptions, column headings, etc -- the text color  would be black, and for any other "important notes" the color will be blue
3. for calculation 
   1. if there is a formulaic then highlight the cell medium gray 
   2. if there is a reference to an external reference,  highlight the cell medium gray with the font being bold color
   3. If there is an error within the workbook, I would like the font to be red.

can should one illustrate one formalize I can use within the conditional formatting command to make this happen in my model?   Want to make model more customized and less manual