There is a quiet treachery hiding in your conditional formatting, and it has nothing to do with the color gold. You set a rule to highlight values greater than or equal to 49, yet a zero lights up like a warning beacon. That is not a quirk. That is a logic gap, and it is worth understanding because it will eventually trip up every spreadsheet user who trusts their eyes over their formulas.
The issue likely stems from how your formula returns the SUM from PLD to PM. When the sum is zero, the cell may not contain a true numeric zero. It could hold a blank string, a text value, or a formula result that evaluates to something visually empty but technically present. Conditional formatting does not care about what you intended. It only evaluates the actual value in the cell. If that value is text, or if your comparison logic is subtly off, then a zero or an empty result can satisfy a rule it has no business satisfying. The rule says "greater than or equal to 49," but the engine may be reading a different type of data entirely, one where the comparison behaves unexpectedly.
Here is what that means for you in practical terms. You cannot assume your conditional formatting is doing what you think it is doing unless you verify the underlying data type. A quick check with the ISNUMBER function or a simple click into the cell to inspect its formula bar will reveal whether you are dealing with a number or a ghost. If the cell contains text, even text that looks like a number, your formatting rules are operating in a separate reality. The same applies when you pull data across sheets. Cross-sheet references and SUM formulas can introduce invisible characters, leading zeros, or error values that shift the goalposts without changing what you see on the surface.
The deeper lesson is that spreadsheets reward skepticism. You are not fighting a mystery; you are fighting a mismatch between what a cell displays and what it actually contains. So before you rewrite your rule or abandon conditional formatting altogether, check the raw output. Use a helper column to confirm the value is numeric and truly zero. Then adjust your rule to account for text or blank results, perhaps by adding an ISNUMBER check or formatting the source formula to return a hard zero instead of an empty string. The fix is straightforward once you stop assuming the spreadsheet is doing what you would do and start asking what it is actually doing. Your data is not broken. Your logic just needs a closer look.