Any color that CONTRASTS with adjacent surroundings to a great degree is going to draw attention, especially if it moves. Fletch in a bow quiver is a good example of contrasting repetitive movement...each time the hand moves (center core of movement) it results in a correspondingly larger 'wave' of contrasting fletch at the end (outer perimeter) of the quiver. It's not the color as much as any contrasting tone, together with the movement, that makes the difference.
Deer (and also deer flies/moose flies) can apparently see blue in some way, deer as a tone of gray (depending on the hue) and the the pesky flies as an actual blue tone, which are apparently) attractive to them (so avoid wearing blue clothing during deer and moose fly season, lol). For deer, if the color tone (regardless of color) matches the tone of the surroundings it wouldn't seem to be a problem. For bow quivers or some hip quivers where the fletch 'bounces' repeatedly with each step or with hand movement, the easy solution is a camo or 'tone correct' fletch cover. Next best is fletching that approximates the surroundings...like natural turkey fletching in the woods...to average out tonal qualities. You still have to contend with the bouncing/movement problem, though.
I guess the bottom line is...if you look at it and can see it moving, so can they.