funky purple shit on the tops of my plants

my plants are growing well but they are starting to get some wierd purple shit on them, im wondering if its a mold or fungus. my plants are growing in a damp area of the woods this might be the cause but im not sure. sorry I have no pics yet has anyone had this on there plants before.

well do you have any idea what the agerage temperature of tyhe area is because with certain strainsk that have a purple in there genetics will show when the temperature drops.

i just read that certain blue strains get purple on them when the temp drops lower than usual.... i read it on attitude seeds....