mahogany

I built some picture frames for a friend a long time ago and they requested another one due to the addition of the there new baby girl. I went to my local wood supplier and they had a very limited supply, I only use it for a small accent piece in the frame. I have completed the frames and the color of the mahogany is not the same shade of color as the other frames. I have one coat of water base poly on them now does anyone have a ideas to darken up the color of the mahogany?