OSC: compacted color string manipulation code

player/lua/osc.lua

@@ -89,7 +89,7 @@ local osc_param = { -- calculated by osc_init()
 }
 
 function osc_color_convert(color)
- return string.sub(color,6,7) .. string.sub(color,4,5) .. string.sub(color,2,3)
+ return color:sub(6,7) .. color:sub(4,5) .. color:sub(2,3)
 end
 
 local osc_styles = {
@@ -1752,7 +1752,7 @@ function validate_user_opts()
  user_opts.held_element_color, user_opts.time_pos_outline_color,
  }
  for _,color in pairs(colors) do
- if string.match(color, "^#%x%x%x%x%x%x$") == nil then
+ if color:find("^#%x%x%x%x%x%x$") == nil then
  msg.warn("'" .. color .. "' is not a valid color")
  end
  end