Which condition becomes TRUE? Answer: Always the first TRUE one, not the latter ones!
See the following example of sub sets.:
Cond. 1: Cell value < 2 red
Cond. 2: Cell value < 4 yellow
Cond. 3: Cell value < 6 green
|
+------+
|Cond.1|
+------+-----+
| Cond.2|
+------------+-----+
| Cond.3|
+------------------+--------------
| Cond.0
+---------------------------------
Cond. 1 is sub set of Cond. 2, both are sub sets of Cond. 3, and all are sub sets of "Cond. 0" (unspecified).
Cond. 0? Yes: Cell value < infinite: The cell keep its original format, because none of the Cond. 1-3 matches.
"Green" only results on 4 und 5 (when limited to integers). At a sub set problem you need this "stairs model" which broadens to its bottom. The condition can land on each of its stairs; in other words: each condition can be met!
The reverse means: Do not put sub sets of results in latter conditions:
Cond. 1: Cell value < 6 green
Cond. 2: Cell value < 4 yellow
Cond. 3: Cell value < 2 red
|
+------------------+
| Cond.1|
+------------+-----+
| Cond.2|
+------+-----+
|Cond.3|
+------+--------------------------
| Cond.0
+---------------------------------
The first condition here overlaps all defined following conditions, which means, they can not become TRUE. If Cond.1 fails, only Cond.0 is possible.