looks like the issue I'm having is really that I was utilizing some style catalog items like "kpi-bar-pct-positive." I'm guessing those styles have lost their colors in R12? Here's my text from the HTML string:
<span style="color:black">
<%=NumberFormat(Cost YTD,"$###,###,###")%>
<%=If(YTD True Up < 0, "<span class=""kpi-bar-pct-positive"">"&NumberFormat(Abs(YTD True Up),"$###,###,###")
&" over charged", "<span class=""kpi-bar-pct-negative"">"&NumberFormat(Abs(YTD True Up),"$###,###,###")&" under charged")%>
</span>
In R11, that "kpi-bar-pct-positive" must have had colors associated with it because no where in here do I have a color setting for green / red but some of the text (specifically the "over charged" or "under charged") was certainly green and red prior to the upgrade.