I had a couple of moles removed and the scar remains with the same colour pigment how can I reduce it?

Options exist. If the scar is pigmented pink or reddish and the procedure was less than a year ago, just wait. The scar will mature and pink color will fade. If you have a darker color present, it may be residual nevus (mole). See your dermatologist/surgeon for evaluation.
Pigment post mole. If your pigment remains after mole removal the mole may not have completely removed. First ensure that the pathology demonstrated benign findings. If the discoloration is due to persistent pigment and not to increased vascularity (erythema or redness), re-excision may be the best way to remove the pigment. If it is red, tincture of time is best but topical silicone sheeting may help expedite this.
Needs attention. If the incision still has the same color as the nevus that was excised, than first see the pathology report. In the report it might describe an incomplete excision. Next ask the operative surgeon if there is any residual pieces of the nevus left. Finally, you most likely need re excision.
Re-excision. If there is pigment left then the mole was incompletely excised. Have it removed by a plastic surgeon.
Hydroquinone. If you have a brownish discoloration after mole removal, it must be a post inflammatory hyper pigmentation. You can reduce with hydroquinone and tretinoin cream sometimes superficial chemical peel or ipl helps.