Light Green/Yellowish New Phal Leaf?

[jrodpad]

Hey everyone. This pic is of my favorite phal hybrid. She's a real beast of a phal and put out tons of flowers on the last spike (some of which are still holding on after 6 months!).

She even put out a new leaf which is growing strong and is already bigger than the last leaf (which was stunted somehow). My only concern is the new light-green/yellowish tint to the inside part of the newest leaf. What's that all about? Anyone seen anything like this before? This phal is a bit root-bound - it has new roots pushing through the vents in the clear plastic pot; but I didn't want to repot until all the blooms faded. Could the leaf color be a result of the need to repot.

If this is a cry for help I want to react quickly, so I appreciate any advise you can give.

Thanks!

- J