To change color of the sheet tab you will have to head towards the home tab and select format from there and then select tab color. From the list of colors given below select the desired color.

Right-click on the tab > Select 'Tab colour' > Select the colour

Simple :)

1) To change the Tab color ---> go to HOME Tab and in the CELLS Group ---> under FORMAT option ---> select Tab color ---> select the desired color.

OR

2) Right-click on the Sheet name given below and select Tab Color option. Select the desired color.