I am not sure what you are refering to. The leaf looks fairly healthy. It seems a bit pale, a bit of brown spotting, but an indoor environment will not produce the vigour of an outdoor plant. I have never grown avocado, so perhaps I am just not seeing the problem that you do.
Oh that's good news! It's a pretty young plant and the leaves where looking absolutely gorgeous the first couple weeks. A strong green colour with no crimping on the sides.
Your avocado is just fine. Slight undulation of leaf edges is pretty normal. And AFAIK, slight yellowish-brownish hue is common too.
With the indoor growing of Advcado's Avoid tap water as the salt will kill it. Also, good drainage a must, and no overwatering as that will also kill it.
Vancouver area municipal tap water has negligible salt content. It is just rainwater running off the North Shore Mountains. A small amount of calcium carbonate is added to neutralize its natural acidity, along with some chlorine, which will evaporate away if the water is left in an open container for a day or more. I've been growing indoor plants in Burnaby for more than 40 years using tap water without seeing any signs of the presence of salt.
