Bet under 0.01 in Blue or Green will not bring you good profit if your bet doesn't hit big Multipliers.
Remember about transaction fees for input and output.
Example :
# Bet 0.005 BTC on Blue and hit x1.1 / 0.005 x1.1 = 0.0055 BTC - Fees ( Input 0.0001 and output 0.0001 ).Your profit only 0.0003.
 
But some players loves to bet on Blue and Green daily with Big Bet because they only need to send 1-3 bets daily and collect nice profit from it everyday.
Example :
# Bet 0.1 BTC on Blue and hit x1.1 / 0.1 x1.1 = 0.11 BTC .Your profit +/- 0.01 less Fees.

Blue Line has very small probability to lose, allows highest bets ( 50 BTC )
Green Line has small probability to lose, but also small winnings.
Small Profit = Small Risk  ><  Big Profit = Big Risk
 
And remember about Rakeback bonus /Sparkling coin, bet more than 0.01 has more chance to get sparkle.
Max Rakeback bonus is 200% from your amount bet.