Java Fern- dark green leaf end

[Knew tooth is]

Could someone please tell me what's going on with my java fern?  As shown in the image, the end of one leaf is dark green. Another leaf of this same size is light green throughout. I've looked on the charts'/diagrams for what might be the problem. But I've been unable to find a similar picture on the these diagrams. Any thoughts would be helpful.

 

[Guppysnail]

This looks like melting (dying). If it is a newer plant it is common for emersed grown leaves to melt while the plant grows new leaves more adapted to surviving being submerged. 

[Knew tooth is]

Thanks Guppysnail, I forgot to mention that this is new growth. 

[Odd Duck]

What are you doing for fertilizer?  The leaves should not be this pale unless this is a new Java fern variety I’ve never seen.  Nearly all varieties have medium to dark green leaves.  A few, rare varieties have slightly lighter green and some even develop a bit of orange on the tips with enough light.  But these leaves don’t look like those varieties.  Can you tell us more about your tank, lights, fertilizer, parameters, filtration, bioload, livestock, etc?

We can give smarter advice if we know more about your set up.

[MattyM]

Is it soft, like it's melting, or it firm like the rest of the leaf? How's the rest of the plant doing? 

[Ray B]

It’s new growth. Mine do the same thing but as the leaf matures the color evens out.

 

[Supermassive]

I agree with @Ray B My narrow leaf java ferns always have that color on the tips of new leaves.

[Milliardo Peacecraft]

@Knew tooth is I seem to get the same thing on my Java ferns as well.  When I see it I usually start adding extra Potasium with the Easy Green and that seems to help.  Granted in general when it comes to any type of Java Fern, you typically can't go wrong with adding extra Potasium, they love it, and no matter how much I add, I've never been able to over do the Potasium such that it caused a problem.  I typically dose it at just about twice the rate seachem gives on the back of the bottle (20 ml per 75 gallons).