Paint bicycle keeping stickers I  have seen a used bicycle for me to buy, which has got me mainly interested, but I don't like the fact it is white. Is it possible to paint it another color keeping the stickers?

Thanks.
To repaint metal, you'll have to strip the current coating. This means you'll have to remove the stickers as well. It is unreasonable to attempt to reuse them, just as it would be silly (or at least ungodly expensive) to try to move a printed image from one T-shirt to another.
You can, however, buy and apply new stickers, if you can find the ones you like. For Rockshox forks they are readily available in several colors. I can also see that stickers for Cube frames are also available.
You can also go with e.g. vinyl wrap applied to existing frame. It can be made to your custom design, for a price.
P.S. My rough estimations are that any sort of repainting of a used frameset is likely to cost at least as much as the bicycle itself. The paint itself may be cheap, but working time to strip the frame and to repaint it are not. Unless you have enough free time to do it yourself, are not afraid to make mistakes and have an empty ventilated garage for a week (it takes several days for several coats of paint to dry).