Modify the calculator bean so that the user can set the background colour of the result box to red, green or blue, via method setResultBground . Then modify the code for the previous exercise by...

the result box to red, green or blue, via method
setResultBground. Then

modify the code for the previous exercise by adding a button that allows the

user to make use of method
setResultBground
(probably via method

JOptionPane.showInputDialog).