What's going on with my leaves?

[*****]

http://tinypic.com/m/jl44k9/2

The pictures seems to not show the problem 100%. The issue is the darker tone in the center of the leaf (Blueish , dark greenish hue)

 

[Orlando737]

http://tinypic.com/m/jl44k9/2

The pictures seems to not show the problem 100%. The issue is the darker tone in the center of the leaf (Blueish , dark greenish hue)

Looks like mag. deficiency from that leaf, but give further details, medium, pot size, feeding regime & someone on here might give a better explanation.
Picture of the whole plant too would help.
Good luck..

 

[Dr. Who]

Add a ca/Mg and next time, use more perlite in your soil mix....

What soil is that?

What are you feeding?