Color is perfect for that stage. Keep doing what you are doing. I tend to try and stay that light into early flower. At the same ratios if you plants begin to darken up in flower then you know the plant is using less but since your solution remain the same it will be time then to lighten up on the nitrogen. Getting really dark leaves early on in your grow will take away a lot of visual clues from the plant in what she is looking for nutrient wise.
Keep up the good work.
FB