Conditional markup field display
You need to implement hook_preprocess_HOOK(&amp;$variables), and add processing there, like this:

&lt;?php

function MYTHEME_preprocess_node(&amp;$variables) {
    // Check if field tid (term id) is filled up
    if (isset($variables-&gt;field_term_color[LANGUAGE_NONE][0]['tid'])) {
        $color = $variables-&gt;field_term_color[LANGUAGE_NONE][0]['tid'];

        $text = '';
        // You need to look up tid of each color
      switch ($color) {
        case 123:
            $text = 'Red is the color of fire.'
            break;
      }

      // Assign value to markup (text) node field
      $variables-&gt;field_markup_field[LANGUAGE_NONE][0]['value'] = $text;
    }
}

?&gt;


You should place the right field names instead of the ones I use, of course.