diff --git a/@graph/graph.m b/@graph/graph.m
index 2d9f9756065ff67cdc831c82c306543693a3f130..d9bab84806d184b80c94d846b2ef791e4944c3bc 100644
--- a/@graph/graph.m
+++ b/@graph/graph.m
@@ -62,6 +62,7 @@ o.legendOrientation = 'horizontal';
 o.legendFontSize = 'tiny';
 
 o.showZeroline = false;
+o.zeroLineColor = 'black';
 
 o.graphSize = [];
 o.xTicks = [];
@@ -132,12 +133,13 @@ assert(ischar(o.xTickLabelAnchor), '@graph.graph: xTickLabelAnchor must be a str
 assert(isint(o.yTickLabelPrecision), '@graph.graph: o.yTickLabelPrecision must be an integer');
 assert(islogical(o.yTickLabelFixed), '@graph.graph: yTickLabelFixed must be either true or false');
 assert(islogical(o.yTickLabelZeroFill), '@graph.graph: yTickLabelZeroFill must be either true or false');
-
 valid_shadeColor = {'red', 'green', 'blue', 'cyan ', 'magenta', 'yellow', ...
                     'black', 'gray', 'darkgray', 'lightgray', 'brown', ...
                     'lime', 'olive', 'orange', 'pink', 'purple', 'teal', 'violet', 'white'};
 assert(any(strcmp(o.shadeColor, valid_shadeColor)), ['@graph.graph: shadeColor must be one of ' ...
         strjoin(valid_shadeColor)]);
+assert(any(strcmp(o.zeroLineColor, valid_shadeColor)), ...
+       ['@graph.graph: zeroLineColor must be one of ' strjoin(valid_shadeColor)]);
 
 valid_legend_locations = ...
     {'south west','south east','north west','north east','outer north east'};
diff --git a/@graph/writeGraphFile.m b/@graph/writeGraphFile.m
index bfa480245b62d9598a40ea6c1aea281dfc3c778d..79b8af745761434223d54139fd6724937af35839 100644
--- a/@graph/writeGraphFile.m
+++ b/@graph/writeGraphFile.m
@@ -212,7 +212,8 @@ if ~isempty(o.shade)
 end
 
 if o.showZeroline
-    fprintf(fid, '%%zeroline\n\\addplot[black,line width=.5,forget plot] coordinates {(1,0)(%d,0)};\n',dd.ndat);
+    fprintf(fid, '%%zeroline\n\\addplot[%s,line width=.5,forget plot] coordinates {(1,0)(%d,0)};\n', ...
+        o.zeroLineColor, dd.ndat);
 end
 
 for i=1:ne