|It sounds like Conditional Formatting should work.|
Let's say the cell where you will be entering Hello is Sheet1!A1
In Sheet 2 click in the box above the Row numbers to select all cells.
Home...Conditional Formatting...New Rule...Format only cells that contain...
Cell Value...equal to...=Sheet1!$A$1...Format...Font...Color...Red
Whenever any cell in Sheet 2 matches the contents of Sheet1!A1, the font will be Red.
Note: The dollar signs ($A$1) are required.
Note 2: You must follow this procedure for each sheet, one by one. It won't work if you group the sheets because the Conditional Formatting feature is not available when sheets are grouped.
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