Remus smiled as Regulus spoke up, recognising the tone. He didn't really mind the others knowing he had restrictions in his colour vision. It was just one of those things he'd never really talked about much. Although, he did have to meet Sirius' raised eyebrow with one of his own. It had been a little difficult to hide the months of colour study he'd done trying to pass his Potions OWL.
"Pads," he said warningly, flashing his friend a teasing grin, "if you really don't want to know where my hands go, you probably shouldn't speculate on the methods by which Regulus will be repaid for the gesture."
He sent another batch of ornaments into the air and directed them over in James' direction, two of them 'tumbling' over each other on the way. "I always thought playing with the decorations was part of the process. Of course, usually that was tinsel and flocking." So saying, he conjured a small handful of flocking and let it 'snow' down on top of Sirius' head with an innocent smile.