Seems to have changed to Yellow when the Bed temperature was switched off by the RAMPS 1.4 board.

Cooling down from 30° C to ambient of about 28° C It should not change the RGB LED to Yellow as it does here.

I need to try adding a 0.1uF capacitor across VCC and GND. As the RAMP 1.4 switches off the bedtemperature a pulse maybe passed that confuse the chip without this capacitor, causing this issue.