I noticed that many comparators insert (in the price list) the same product of different colors. This is because very often the color also influences the price. Is it possible to do it with my project?
There's a couple of options here. If color is a field in your feeds you could combine it with the product name using a Text After filter which supports %FIELDNAME% placeholders so if the field is "color", a Text After filter configured as follows;
(without the quotes, but notice the leading SPACE so that it is separated from the rest of the product name)
However, this would result in separate product pages (by color). If you did want to compare by colour / price for the same merchant on product pages then you could add color as a custom field and remove the duplicate prevention mechanism which is described in this comment (as well as how to restore it if required). You could then add a color column to the price comparison table in html/prices.php adding an appropriate header:
...and in the loop:
<td><?php print $product["color"]; ?></td>