my own hair color is black and my hairpiece is 1B black color but unfortunately the parameiter becomes lighter to brownish how would i color it and with which product?

Ahmed,
I suggest using a color blender called 'Back 2 Natural.' It's designed specifically to blend the color of a hair system to the color of your own hair. This is a great product and it's available form adfhair.com. You just put it on a comb and run it through your own hair where it meets the hair system and it will blend the 2 colors together.
Regards,
John
http://toplace.com/

Thanks John,
But which color should i choose since my own hair is black and the
Hairpiece original color is black..
The available colors are light,medium and dark blonde
Or light,medium and dark brown?

Dark ash brown is the one you want. My experience of this product is that, ideally, it should be used from the word `Go`, on your new system, as a maintenance product and to prevent oxidation [colour-lift] It`s less effective once more severe colour-lift has already happened, as it tends to wash out again, reasonably soon. Once that happens, you`re best off using an over-the-counter colouring product.... L`oreal make many as do other companies...apply a small amount along the teeth of a comb [don`t overload the comb] and comb it into damp hair....keep it off the lace, or you`ll stain it permanently. Ignore the ` timing` instructions on the pack...... system hair absorbs colour much much faster than growing hair, so only leave it on for about 3 minutes max.,otherwise it`ll go far too dark . Rinse it off under running water [such as a shower-head] by directing the water through the underside of the system, away from the lace.

Thank paul..
I think im going with L'oreal since my hairpiece is old
But which color should i choose?

You said your own hair is black , so that`s what you have to get..... the timing is crucial ...do NOT leave the product on the hair for more than a few minutes.....try 3 minutes, then rinse it out, allow it to dry and see how it looks....you can re-treat it if needs be......leaving it on too long will result in it going far too dark [unnaturally so] and the only thing you could do then is add colour to your own hair to darken that too ! Just keep it off the lace....you can always just do a ` set` length of perimeter/ area first ,so as to avoid feeling ` pressured` for time..... rinse that bit out/off , and move on to do the next bit and so on...just take your time..that way you won`t make a mess of it. You should use rubber gloves to protect your skin. Let us know how you got on.