Improve color system, rofi theme formatting system

rofi/default.nix

@@ -1,13 +1,18 @@
 { pkgs, ... }:
 
-{
+let
+  colors = import ../colors;
+  theme = colors.theme;
+in {
   home.packages = with pkgs; [
     (pkgs.callPackage ./power.nix { })
     wmctrl # TODO: add as dependency of rofi-power
   ];
   programs.rofi = {
     enable = true;
-    theme = "theme";
+    inherit theme;
   };
-  home.file.".config/rofi/theme.rasi".text = import ./theme.nix;
+  home.file.".config/rofi/${theme}.rasi".source = pkgs.substituteAll ({
+    src = ./theme.rasi;
+  } // colors.colors);
 }

rofi/theme.rasi

@@ -1,6 +1,4 @@
-# Modified from https://github.com/undiabler/nord-rofi-theme
-let colors = import ../colors; in
-''
+/* Modified from https://github.com/undiabler/nord-rofi-theme */
 configuration {
   font: "Noto Sans Mono 12";
 	width: 30;
@@ -18,7 +16,7 @@ configuration {
 
 * {
   background-color: transparent;
-  highlight: underline bold ${colors.fg1};
+  highlight: underline bold @fg1@;
 }
 
 window {
@@ -40,16 +38,16 @@ mainbox {
 }
 
 message {
-  color: ${colors.bg0};
+  color: @bg0@;
   padding: 5;
-  border-color: ${colors.fg0};
+  border-color: @fg0@;
   border:  0px 2px 2px 2px;
 }
 
 inputbar {
-  color: ${colors.fg0};
+  color: @fg0@;
   padding: 11px;
-  background-color: ${colors.bg1};
+  background-color: @bg1@;
 }
 
 entry, prompt, case-indicator {
@@ -64,23 +62,22 @@ prompt {
 listview {
   padding: 8px;
   border: 0;
-  background-color: ${colors.bg0}e5;
+  background-color: @bg0@e5;
   dynamic: false;
 }
 
 element {
   padding: 3px;
   border-radius: 4px;
-  text-color: ${colors.fg0};
+  text-color: @fg0@;
 }
 
 element selected.normal {
-	background-color: ${colors.primary};
-	text-color: ${colors.bg0};
+	background-color: @primary@;
+  text-color: @bg0@;
 }
 
 element-text, element-icon {
   background-color: inherit;
   text-color: inherit;
 }
-''