Try to save this XML value in a variable and pass the variable into the Fusionchart.
string value =
@"<graph >
<colorRange>
<color minValue='0' maxValue='75' code='FF654F' label='Bad' />
<color minValue='75' maxValue='90' code='F6BD0F' label='Moderate' />
<color minValue='90' maxValue='100' code='8BBA00' label='Good' />
</colorRange>
<pointers>
<pointer value='92' />
</pointers>
</graph>";
Literal1.Text = InfoSoftGlobal.FusionCharts.RenderChartHTML("FusionCharts/HLinearGauge.swf", "", value, "chart", "448", "250", false);