The sky gets dark when riding a minecart

Hey,i'm RealATO and i found a really strange bug.

When I am riding a minecart the sky gets dark or maybe the clouds only.

Steps to reproduce:
1.Place a rail
2.Right click the minecart/Ride the minecart
3.Notice that the sky gets darker.

I hope i helped you by reporting this bug.

Please solve it,because I don't want the sky to get dark when riding a minecart.