how to paint match stairs

[Kirito]

hey, i got stairs up to first floor which are nicely painted and Stairs from first floor to second need painting and are different colour.

Got two question.

1) How to paint the stairs from first to second floor, I got a wood stain but the white gloss paint that is already painted does not like it. should i remove the paint first or undercoat it with something

2) I cant find the paint or paint type used on the stairs from ground to first floor, I though it a walnut wood stain but the wood stain I tried to paint second floor stairs with look very transparent

I have attached photos of the already painted stairs and the stairs I want to paint

 

[Chivas69]

Guessing you mean the stair rails and spindles. Wood stain is painted from bare wood. It gets darker the more coats you put on.it looks like you're trying to put wood stain on top of white gloss. You would be better sanding it back down to bare wood then the wood stain will look correct. A big job !

 

[88v8]

It's quite usual in a Period house to have polished/stained banister rails & newel posts, and painted spindles.
So I would not be trying to stain them, even if it were possible to stain over paint.