tmux: Use hex values for colors

Taken from my st fork (Originally the tango theme I believe).

.config/tmux/tmux.conf

@@ -244,12 +244,12 @@ bind d {
 }
 
 ## Theming
-set -g @accent_color 'brightyellow'
-set -g @ui_color 'brightblack'
-set -g @sync_color 'brightred'
-set -g @text_fg 'black'
+set -g @accent_color '#fce94f' # brightyellow
+set -g @ui_color '#757773' # brightblack
+set -g @sync_color '#ef2929' # brightred
+set -g @text_fg '#5e6466' # black
 
-set -g status-style bg=default,fg=white
+set -g status-style bg=default,fg='#d3d7cf' # white
 set -g message-command-style 'bg=default,fg=#{@accent_color}'
 set -g message-style 'bg=#{@accent_color},fg=#{@text_fg}'
 set -g mode-style 'bg=#{@accent_color},fg=#{@text_fg}'