We had a nagging small leak that had similar Bilge effects.
We found it was associated with a
Heavy Rain.
This is a technique of using your "Colored water" too.
On my H430, I noticed that all non diesel, "inner hull exposed" compartments flow to the main bilge.
We bought some cheap WHITE painter's rags [face cloths work too]
Then placed a White cloth "detector" in those compartments.
Finally only one "detector" was getting wet.
It was near the Port side life rail gate, also the main head area.
Then we used the Food Color dyed water on the weather deck near the gate. [5 gal bucket].
Found it!!!
The weather deck has a "rain/wave splash" dump area about 2 foot wide as a "spill way" overboard.
All of the Port side deck water, flows overboard through that "spill way" and over the
rub rail.
Ours was a Deck to hull leak seam leak.
Jim...
PS: The leak was stopped by a simple trick, that took us 5 minutes to fix.
Also the previous owner tried to solve it, but his crappy method didn't work.