Splitting the code into single files is done. \o/

src/effect_static.cpp

@@ -0,0 +1,13 @@
+#include "effect_static.h"
+#include "functions.h"
+#include "my_fastled.h"
+
+StaticEffect::StaticEffect(CRGB col) {
+    color = col;
+}
+
+void StaticEffect::loop() {
+    EVERY_N_SECONDS(1) {
+        clear(window, color);
+    }
+}