Controlling Shade in Indigo Dyeing of Denim

If shade is getting:

Redder- Increase the conc. of Caustic , slightly decrease the conc. of Hydro
Redder, Duller- Increase the con. of hydro
Greener, Paler- decrease the con. of hydro
Greener, duller- Increase the con. of caustic
Bronzing- Increasing the con. of Hydro