People are fond the word "Luck" . Generally Luck means Athista or Fortune for them to get success without much effort. 

Actually the word Luck is origin of the word from Lagna  or Ascendant in Horoscope. 

According to Vedic Astrology 9th house signifying  fortune or Luck . If someone  wants to be a luckiest person then they should see who is 9th lord and try to use 9th lord gems, colors, direction etc., so that they will have a chance to become fortune in his/her life. 

Here is the list of Lucky planets for each ascendant and colors. For identifying the correct gems, direction better check with your astrologer. If they use the color in day to day they will prosperous and get more success in all his effort. 

1) Mesa lagna - 9th lord is Jupiter the color of Jupiter is Yellow.
2)Virgo Lagna -9th lord is Saturn , Use the color Black.
3) Gemini Lagna -9th lord is Saturn , use the color Black 
4) Cancer or Karkata Lagna-9th lord is Jupiter and the color of Jupiter is Yellow.
5) Leo Lagna - 9th lors is Mars and use the color Red. 
6) Virgo Lagna -9th lord is Venus use the color sighning White.
7) Libra Lagna -9th lord is Mercury and use the color Green.
8)Scorpio Lagna -9th lord is Moon and use the color Normal white without much sighning. 
9) Saggitarious Lagna -9th lord is Sun and use the color Orange.
10) Capricorn Lagna -9th lord is Mercury and use the color Green.
11) Aqurious Lagna -9th lord is Venus and use the color shining White. 
12) Pisces lagna -9th lord is Mars and use the color Red.