LankyBox01 codeteacher
DO NOT USE px, i would suggest you use the true type font size system pt.
Also try this
<p><font color="red" size="12pt">This is some text</font></p>
<p><font color="magenta" size="10pt">This is some small text</font></p>
<p><font color="blue" size="8pt">This is some smaller text</font></p>
<p><font color="green" size="6pt">This is the smallest text</font></p>