HTML/Javascript

Question

Hi I have a question want to know if anyone can help me.. I juz started to program in HTML and trying to make a program where in you have three color buttons red, blue and green and first time when u press the color it should display red when i press red button and second time when i press blue button it should display text changed from red to blue and when i press red it should display text changed from blue to red so on and so forth.. how do i go abt wri\ting html/javascript code for this>