Update block pallette slightly to more saturated colours in order to increase constrast between block color and stroke color (#1323)

libs/core/images.cpp

@@ -25,7 +25,7 @@ void RefMImage::makeWritable() {
 /**
  * Creation, manipulation and display of LED images.
  */
-//% color=#5C2D91 weight=31 icon="\uf03e"
+//% color=#7600A8 weight=31 icon="\uf03e"
 //% advanced=true
 namespace images {
 /**