added visual color palette

sketch.tcl

@@ -5,7 +5,11 @@ wtk::bind .c <B1-Motion> {
    .c create line $x $y %x %y -fill $color
    set x %x; set y %y
 }
-wtk::grid [wtk::frame .tools] -column 0 -row 1
-wtk::grid [wtk::button .tools.black -text Black -command "set color black"] -column 0 -row 0
-wtk::grid [wtk::button .tools.blue -text Blue -command "set color blue"] -column 1 -row 0
-wtk::grid [wtk::button .tools.red -text Red -command "set color red"] -column 2 -row 0
+
+set colors "black blue red green yellow orange brown"
+wtk::grid [wtk::canvas .palette -background #cccccc -width 400 -height 30] -column 0 -row 2
+set x 10
+foreach i $colors {
+    .palette bind [.palette create rectangle $x 5 [expr {$x+7}] 25 -fill $i] <1> "set color $i"
+    incr x 10
+}