In Up or Down, a colour clue while the giver is loaded means that the leftmost touched card can start the stack. If the stack for that colour has already started, the clue is treated as a Referential Play Clue.
This is different from the Loaded Colour Clues convention, which requires that the receiver is loaded.
If a Loaded Direct Colour Clue is given while the giver is loaded on the same colour, the receiver should respond with the clue matching the card.
colour for START cards (giver should play START next)
rank for 1/5 cards (giver should respond with colour if receiver has START, otherwise giver should play their own card next)
If giver plays, the receiver receives PTD on the leftmost unclued slot. Thus, giver can follow up with a rank clue after receiver responds if slot 2 is not safe, which is not loaded.