public void setDecorationBackgroundColor(Color decorationBackgroundColor) {
        this.decorationBackgroundColor = decorationBackgroundColor;

        if (days != null) {
            for (int i = 0; i < 7; i++) {
                days[i].setBackground(decorationBackgroundColor);
            }
        }

        if (weeks != null) {
            for (int i = 0; i < 7; i++) {
                weeks[i].setBackground(decorationBackgroundColor);
            }
        }
    }