Hello Neeraj
Welcome to the OutSystems!
It seems you are looking for the simple method to change the Input box Color if someone clicks on the Button.
Please check this URL and click on Change Color Button. Please confirm if you are looking something like this - https://personal-9qwkrkgl.outsystemscloud.com/ForumHelp/DataScreen?_ts=637599900604926215
Just to try, you can put the color name like yellow, red, black, green in inputbox and try updating the color of input box.