This type of goo shifts in color depending on specific stimuli a mhoat experiences; what causes the color shift is unique from one mhoat to the next and if two mhoats share a method of color shift (such as emotions), this does not mean they will share the same goo color. This color shift can affect all of the goo or only parts of the goo and can be caused by different stimuli such as emotions, seasons, weather, etc.
When a character has this trait, it will not be required to have Single Tone Goo, Double Tone Goo, or Triad Goo, as it overrides the color limit. However, if it is specified that this trait only affects certain parts of the Mhoat and not the entire body, you will still need to heed the color limits and thus require the traits.
When submitting a mhoat with this design you will need to include a set of colors and either symbols or words outlining what causes the goo color to shift. You will also need to include in the comment section of the design approval the exact method of color change.