They need plenty of bright light. Direct sunlight is best for this plant for a few hours a day. Do not leave in the scorching sun. They can handle low light levels, however, the sun brings out more colours.
Keep the soil moist but do not over water as they do not like too wet or too dry.
Keep your Croton warm between 18-27 degrees and slightly on the higher end of humidity. Spray with water bottle once a week.
This plant is great for indoor environments, as it filters airborne toxins.