Yeah salmon vary in color so dont go by that... Like Gore said go more on the feel of the fish. Now this is personal preference but I got for a 2:1 sugar to salt with additional seasonings. I find more sugar and its too sweet for me... it's just my sweet spot. Waht you didnt mention though was how long did you cure it for? It certainly looks ready though. I'm sure it'll come out great.
1 - 100 lb. self-made cylinder grill/smoker
1 - 100 lb. self-made cylinder smoker
1 - 20 gal. self-made grill/smoker
1 - 25 gal. self-made vertical smoker
1 - 120 gal. self-made trailer stick-burner