It sounds like a nutrient deficiency. An aphid infestation heavy enough to upset the plant would cause at least some of the leaves to crumple.

If you've only recently planted it, the roots are still settling and maybe not being very efficient. I wouldn't use any fertiliser on it until you've established that it's getting plenty of water. Don't just rely on the top surface being wet - it's easy to water and soak the top inch or so, and still have dry soil underneath.

It's not going to die on you suddenly so don't panic - you've got time to try first, more water, and if that doesn't work, some fertiliser.

Meanwhile - can you tell us more about the pale leaves? Is it all of them, or are the new leaves still dark green? Is it the whole leaf, or are the veins dark green with yellow bits between?