diff --git a/colors_test.go b/colors_test.go
new file mode 100644
index 0000000..ff93b48
--- /dev/null
+++ b/colors_test.go
@@ -0,0 +1,77 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/nsf/termbox-go"
+)
+
+func TestApplyAnsiCodes(t *testing.T) {
+	none := termbox.ColorDefault
+
+	tests := []struct {
+		s     string
+		fg    termbox.Attribute
+		bg    termbox.Attribute
+		fgExp termbox.Attribute
+		bgExp termbox.Attribute
+	}{
+		{"", none, none, none, none},
+		{"", termbox.ColorRed, termbox.ColorRed, none, none},
+		{"", termbox.AttrBold, none, none, none},
+		{"", termbox.ColorRed | termbox.AttrBold, none, none, none},
+
+		{"0", none, none, none, none},
+		{"0", termbox.ColorRed, termbox.ColorRed, none, none},
+		{"0", termbox.AttrBold, none, none, none},
+		{"0", termbox.ColorRed | termbox.AttrBold, none, none, none},
+
+		{"1", none, none, termbox.AttrBold, none},
+		{"4", none, none, termbox.AttrUnderline, none},
+		{"7", none, none, termbox.AttrReverse, none},
+
+		{"1", termbox.ColorRed, none, termbox.ColorRed | termbox.AttrBold, none},
+		{"4", termbox.ColorRed, none, termbox.ColorRed | termbox.AttrUnderline, none},
+		{"7", termbox.ColorRed, none, termbox.ColorRed | termbox.AttrReverse, none},
+
+		{"4", termbox.AttrBold, none, termbox.AttrBold | termbox.AttrUnderline, none},
+		{"4", termbox.ColorRed | termbox.AttrBold, none, termbox.ColorRed | termbox.AttrBold | termbox.AttrUnderline, none},
+
+		{"31", none, none, termbox.ColorRed, none},
+		{"31", termbox.ColorGreen, none, termbox.ColorRed, none},
+		{"31", termbox.ColorGreen | termbox.AttrBold, none, termbox.ColorRed | termbox.AttrBold, none},
+
+		{"41", none, none, none, termbox.ColorRed},
+		{"41", none, termbox.ColorGreen, none, termbox.ColorRed},
+
+		{"1;31", none, none, termbox.ColorRed | termbox.AttrBold, none},
+		{"1;31", termbox.ColorGreen, none, termbox.ColorRed | termbox.AttrBold, none},
+
+		{"38;5;0", none, none, termbox.ColorBlack, none},
+		{"38;5;1", none, none, termbox.ColorRed, none},
+		{"38;5;8", none, none, termbox.Attribute(9), none},
+		{"38;5;16", none, none, termbox.Attribute(17), none},
+		{"38;5;232", none, none, termbox.Attribute(233), none},
+
+		{"38;5;1", termbox.ColorGreen, none, termbox.ColorRed, none},
+		{"38;5;1", termbox.ColorGreen | termbox.AttrBold, none, termbox.ColorRed | termbox.AttrBold, none},
+
+		{"48;5;0", none, none, none, termbox.ColorBlack},
+		{"48;5;1", none, none, none, termbox.ColorRed},
+		{"48;5;8", none, none, none, termbox.Attribute(9)},
+		{"48;5;16", none, none, none, termbox.Attribute(17)},
+		{"48;5;232", none, none, none, termbox.Attribute(233)},
+
+		{"48;5;1", none, termbox.ColorGreen, none, termbox.ColorRed},
+
+		{"1;38;5;1", none, none, termbox.ColorRed | termbox.AttrBold, none},
+		{"1;38;5;1", termbox.ColorGreen, none, termbox.ColorRed | termbox.AttrBold, none},
+	}
+
+	for _, test := range tests {
+		if fgGot, bgGot := applyAnsiCodes(test.s, test.fg, test.bg); fgGot != test.fgExp || bgGot != test.bgExp {
+			t.Errorf("at input '%s' with '%d' and '%d' expected '%d' and '%d' but got '%d' and '%d'",
+				test.s, test.fg, test.bg, test.fgExp, test.bgExp, fgGot, bgGot)
+		}
+	}
+}