Silvery Brown Spots/Unhealthy looking Impatiens
I planted some impatiens (Burpee's 30959 - Flavours Hybrid Mix) from seed and they were doing really well as seedlings. I transplanted the majority outside but kept one indoors.
My outdoor plants look stunted and the leaves are curling downwards (though I've never grown impatiens before so I'm not sure if this is normal) and started to develop silvery-brown patches on their leaves. Some have become slightly yellow with white spots and have fallen off. The color of the entire plant also has purple streaks (is this normal?).
The plant I kept in doors has grown much taller with straighter leaves and are a lighter color, so I'm really concerned that something is very wrong with the outdoor ones.
It's not downy mildew as there is nothing like that on the bottom of the leaves. I'm scared it may be Necrotic Spot Virus but they don't look like the pictures I've seen of it.
I'm new to gardening but have loved all of my plants since they sprouted and I'm not sure what I should do. Does anyone know what this might be? Do you think it may be treatable and how?
Thanks so much for your help.