I have a question concerning the different shades of white. This is a picture of one of my sketches drawn on an A4 paper scanned to my Macbook. I wanted to resize the image so that it fits on a larger horizontal frame, so I pasted the original scan onto a white background that I had created in photoshop. To my surprise, when I uploaded it to my website and look at it on a window pc, it clearly shows two different shades of white, with the original A4 area looking grey/blueish. So I opened it in photoshop again and sampled the color and get the result below:
The white shade sampled from the circle 1 shows to be from the red section, while the white shade sampled from the circle 2 shows to be from the blue section of the color spectrum.
And the third screenshot is when I change the layer to multiply, and apply a solid color layer underneath, then it clearly shows that the layer 0 has two different shades of white on it.
My question is, can I replace the color of the "blue" white area with the white shade from the red "white" area?
Thank you in advance.