First time!

So I dunk some rockwool in water with a ph of 5.7, the rock wool sits in a jar and the temperature is about 75-80 degrees, and and about a week later it has popped up. The stem is pale white with the first little pedals have a pale brown/yellow discoloration to them. I'm thinking maybe a lack of light? Or maybe this is normal for the first couple days for the seedling after popping out until it can gather some light? Any help please!
[SUB].. , [/SUB]
. [SUP].[/SUP] .. .[SUP]: ;..[/SUP]
.[SUP]. [/SUP][SUP]';..GrowinNature..[/SUP]
;
:

pic will help

I put it underneath my light and a few hours later it the pedals were radiating with green color!!! Thanks though!

Quite a few plants do that.In potatoes you can see them sprout pretty damn long stems in the dark and once they get enough light they green up and throw leaves really fast.