Painting - touch up painting

Have had my interior painted ( in Nov. ) after the holidays I noticed I needed to do some touch ups on my walls. We are using the paint the painter used-BUT it comes out lighter---Please tell me what I am doing wrong? We have tried brush,roller & even primer before painting over that.....Please help!!!!


Thank you,
Gwen

Has the touch-up paint been frozen at any time?

Has the t/u paint been mixed thoroughly?

Is there a smoker in the house, or have candles been burning close by?

Are you sure its the same paint?

Is it possible that the original color, (pre Nov.) was a darker color, and it needed a second coat, so you are seeing the 'true' color now with the t/u? (with the t/u being the needed second coat, because the darker original color was bleeding through?)

What type of paint is being used: flat, eggshell, satin, or semi-gloss?

Was the original paint job (pre Nov.) the original builders flat?

Specifically, is it the t/u out of the same can? There will be slight variations from one can to the next, even with the exact same brand/sheen/formulation.

This was latex, yes?