You will have to start your th tag with a <th style="…"and add the color. Then start your colspan tag!
Its confusing because you can add more then one style with a semicolon, but you need opening and closing tags to add more then one tags.
example below for lesson 9 on HTML basics lll
TAGth style="color: red"TAGTAGcolspan="2"TAGFamous Monsters by Birth YearTAG/thTAG
**had to put “TAG” because it wouldnt show the code