I have been testing different finishes for the Baltic Birch and Oak Plywood I use. I found that an oil finish looks the best. I am currently using "Watco Danish Oil. Below are my test. The top image is taken with a flash, the lower image is with natural lighting (in the sun). I have some colored playing pieces on the samples so you have a color reference. The color in the Watco oil is very light and it is very subtle. Select any image to see a larger version of the image in a new windows (tab).
From left to right the oil colors are:
Plain Teak Oil, no color