To just modify key properties, press the key (1-4) you desire to modify. Then use next to go through the available adjustable properties.
To "reset" the key:
Press the and Hold the Key(1-4) key type (self, DVE, auto, chroma), same as selecting how the keyer will function, You should see "reset key" come up in the display, then press the softkey to reset it to default based on what input the keyer has assigned to it.
Carbonite_Operation-Manual Page 32-41 explains all about keyers
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