diff --git a/apps/openstmap/imagefilter.js b/apps/openstmap/imagefilter.js
index 07ff1acc8d..aa976dc0fa 100644
--- a/apps/openstmap/imagefilter.js
+++ b/apps/openstmap/imagefilter.js
@@ -8,7 +8,7 @@ Stick this in a file so we can
 function imageFilterFor3BPP(srcData, dstData, options) {
   options = options || {};
   if (options.colLo === undefined)
-    options.colLo = 115; // when adding contrast/saturation, this is the max saturaton we add
+    options.colLo = 140; // when adding contrast/saturation, this is the max saturaton we add
   if (options.colHi === undefined)
     options.colHi = 250;
   if (options.sharpen === undefined)
@@ -103,4 +103,4 @@ function imageFilterFor3BPP(srcData, dstData, options) {
       idx+=4;
     }
   }
-}
\ No newline at end of file
+}
diff --git a/apps/openstmap/test/index.html b/apps/openstmap/test/index.html
index 654bd0d218..f17761b9c5 100644
--- a/apps/openstmap/test/index.html
+++ b/apps/openstmap/test/index.html
@@ -17,7 +17,7 @@
     <input type="checkbox" id="finaldither" checked></input><span>Final dither (Bangle.js preview)</span><br/>
     <input type="checkbox" id="sharpen" checked></input><span>Sharpen</span>
     <input type="checkbox" id="dither"></input><span>Line Dither</span><br/>
-    <input type="range" id="slider_lo" min="0" max="255" value="115">Lo threshold<br/>
+    <input type="range" id="slider_lo" min="0" max="255" value="140">Lo threshold<br/>
     <input type="range" id="slider_hi" min="0" max="255" value="250">Hi threshold<br/>
 
     <script src="../../../webtools/heatshrink.js"></script>
@@ -104,8 +104,8 @@
       }
 
       document.getElementById("getmap").addEventListener("click", update);
-      document.getElementById("slider_lo").addEventListener("mouseup",update);
-      document.getElementById("slider_hi").addEventListener("mouseup",update);
+      document.getElementById("slider_lo").addEventListener("change",update);
+      document.getElementById("slider_hi").addEventListener("change",update);
       document.getElementById("finaldither").addEventListener("click",update);
       document.getElementById("sharpen").addEventListener("click",update);
       document.getElementById("dither").addEventListener("click",update);