Coreldraw
You asked: How to use blend in coreldraw ?
Draw a square (hold Ctrl while dragging with the rectangle tool), then change outline color (i.e. Blue). Make a duplicate (click on the + key of the Numeric Keypad or copy/paste), then change the color of the new square (i.e. to Cyan). Now, select both squares and go to Effect/Blend, that will open the Blend Docker.