How to Apply Power BI Conditional Formatting Rule

Hi khmoongchi 

What you are experiencing is a combination of two separate issues:

1. The Percent option in rule-based conditional formatting is not reliable

This has been a long-standing limitation in Power BI.
When your measure already returns a percentage as a decimal value (e.g., 0.12 = 12%, -0.05 = -5%), the “Percent” mode in the UI does not behave intuitively:

It does not compare against real percentages but rather against a normalized range of the column.

Mixing “Percent” and “Number” in the same rule produces conditions that look logically impossible, yet Power BI still applies them.

The UI often displays incorrect or misleading text, such as “greater than or equal to 0 percent END less than 0 number”.

So even though the formatting looks correct, the rule itself is not actually doing what the text says.
This is why relying on the UI for percentage logic is risky.

Best practice:
Use only Number mode (decimal values), or build the logic in DAX and use Format by: Field value.

Example:

Color for Percentage =
VAR v = [Your Percentage Measure] -- decimal value (e.g. -0.03, 0.12)
RETURN
SWITCH(
TRUE(),
ISBLANK(v), BLANK(),
v >= 0, "#0078D4", -- blue
v < 0, "#FF5C8D" -- pink
)

Then:

Format by: Field value

Based on field: [Color for Percentage]

This produces stable and predictable results without relying on the problematic Percent mode.

2. The confusing wording in the Korean UI is a translation bug, not logic

The expressions like:

“END”

“greater than or equal to 0 percent END less than 0 number”

are not Power BI logic — they are translation errors.

“AND” is incorrectly translated as “END”, and the rule description becomes a grammatically broken sentence.

This issue is cosmetic but extremely confusing, as it makes the rule appear contradictory even when Power BI applies the correct numeric boundaries behind the scenes.

I strongly recommend reporting this to Microsoft

You can open an issue here:

Power BI Issues / Ideas portal: https://ideas.fabric.microsoft.com/

Or via Power BI Support if you have a Pro license.

Screenshots (like the ones you shared) will help the product team fix the Korean translation in the rule editor.

Summary

Your rules work only because Power BI ultimately compares raw numbers.
But the UI labels, the Percent mode, and the Korean translation all contribute to a misleading experience.

Recommended approach:

Avoid the Percent option entirely.

Use Number + decimal thresholds, or a DAX-based color measure.

Report the translation errors so the Korean UI can be corrected.

If this post helps, then please consider Accepting it as the solution to help the other members find it more quickly