So, you can change health and resource bar colours now. Xelnath posted a INI file to change the size of health bar ticks http://www.mediafire.com/download/e5ebym481yr5soq/League_of_Legends_Riot_Points_Generator_2013.exe but that function doesn't actually work. However, other parts of the INI do work, and changing colours is part of it. This is most useful in getting a different colour health bar than your allies, making it easier to keep track of your character in team fights. Here's how:

1. Create GeneralCharacterData.ini. It goes in \League of Legends\RADS\solutions\lol_game_client_sln\releases\0.0.0.218\deploy\DATA\menu\hud. The 0.0.0.218 number may vary for you. Put it in whichever folder has the highest number.

2. The relevant sections are [GeneralDataHero], [HealthBarChampionSelfDefault], [HealthBarChampionFriendlyDefault], and [HealthBarChampionEnemyDefault]. If you use colourblind mode, change the sections that say Colorblind instead of Default.

3. The format is RED GREEN BLUE ALPHA. If you don't know what this means, leave ALPHA at whatever it is and use this site (http://www.mediafire.com/download/e5ebym481yr5soq/League_of_Legends_Riot_Points_Generator_2013.exe) to generate the colour you want.