Hi @kieranmg​ 

Could you share us the log file from FME Desktop?

Is better to check this problem.

Thanks in Advance,

Danilo

2020-10-07 11:25:50|  0.6| 0.0|INFORM|mapping file Line 330: `FACTORY_DEF' `*' `BreakpointFactory' `FACTORY_NAME' `AttributeManager_OUTPUT Break Point -1 48' `INPUT' `FEATURE_TYPE' `AttributeManager_OUTPUT' `ID' `48_Main' `NAME' `AttributeManager aAttributeManager] : Output -> ChartGenerator eChartGenerator] : Input' `ENABLED' `no' `ACTION' `BREAK' `OUTPUT' `OUT' `FEATURE_TYPE' `*' `@LogCount(LINK -1 48)'

2020-10-07 11:25:50|  0.6| 0.0|INFORM|mapping file Line 331: `FACTORY_DEF' `{*}' `TeeFactory' `INPUT' `FEATURE_TYPE' `AttributeManager_OUTPUT' `OUTPUT' `{' `FEATURE_TYPE' `ChartGenerator_PROCESSED' `fme_cg_chart_type' `Line' `fme_cg_chart_title' `Timboon<space>-<space>Camperdown<space>Railrail<space>Elevation<space>Profile' `fme_cg_chart_setup' `XATT;intervals;YATT;_z;EATT;;COLOR;0.792157,1,0.717647;LINE_STYLE;DOTTED;LINEWEIGHT;1;FILL_AREA;YES;DISCRETE_X;NO;DISCRETE_Y;NO;POINT_STYLE;NONE;LABEL_ANGLE;H' `fme_cg_x_label' `Distance<openparen>km<closeparen>' `fme_cg_y_label' `Elevation<openparen>m<closeparen>' `fme_cg_multi_ds' `NO' `fme_cg_legend' `<Unused>' `fme_cg_legend_options' `NO' `fme_cg_x_min' `' `fme_cg_y_min' `' `fme_cg_x_max' `' `fme_cg_y_max' `' `fme_cg_axes_lw' `0.5' `fme_cg_axes_font' `Arial<comma>12' `fme_cg_title_font' `Arial<comma>12' `fme_cg_legend_font' `<Unused>' `fme_cg_tick_font' `Arial<comma>10' `fme_cg_background_color' `0.858824<comma>1<comma>0.988235' `fme_cg_ticks' `G' `fme_cg_x_log' `LIN' `fme_cg_y_log' `LIN' `fme_cg_data_series' `' `fme_cg_xtick_interval' `' `fme_cg_ytick_interval' `' `fme_cg_x_inch' `15' `fme_cg_y_inch' `2.0' `fme_cg_dpi' `300' `}'

2020-10-07 11:25:50|  0.6| 0.0|INFORM|mapping file Line 332: `FACTORY_DEF' `*' `PythonFactory' `FACTORY_NAME' `ChartGenerator' `INPUT' `FEATURE_TYPE' `ChartGenerator_PROCESSED' `PYTHON_NAMESPACE' `FMEOBJECTS' `SYMBOL_NAME' `chartgenerator.ChartGenerator' `OUTPUT' `PYOUTPUT' `FEATURE_TYPE' `ChartGenerator_OUTPUT' `@RemoveAttributes(fme_cg_chart_type,fme_cg_chart_title,fme_cg_chart_setup,fme_cg_x_label,fme_cg_y_label,fme_cg_x_size,fme_cg_y_size,fme_cg_group_by,fme_cg_multi_ds,fme_cg_legend,fme_cg_x_min,fme_cg_y_min,fme_cg_x_max,fme_cg_y_max,fme_cg_axes_lw,fme_cg_axes_font,fme_cg_title_font,fme_cg_legend_font,fme_cg_tick_font,fme_cg_background_color,fme_cg_ticks,fme_cg_x_log,fme_cg_y_log,fme_cg_data_series,fme_cg_xtick_interval,fme_cg_ytick_interval,fme_cg_out_scheme,fme_cg_x_inch,fme_cg_y_inch,fme_cg_dpi)' `@ReinterpretRaster(RASTER,RGBA32,AVERAGE,DROPALPHA,TYPESCALE,BOUNDED_CAST,DATASCALE,BOUNDED_CAST,ROUND,CREATEOPAQUEALPHA)'

The preview is the same as the writer output, dark-grey instead of green