Colorize expanded tabs

[qwweeeit]

Hi all,
from a string embedding tabs I want to colorize them when expanded:

# Starting from a string:
a= '1234\t5678\t\t90\nqwerty\nasdfg'
# which embeds both tabs and lfs

# printing it you obtain:
print a
# 1234    5678            90
# qwerty
# asdfg

# print automatically expands tabs and interprets the NL.

# to colorize the expanded tabs, I tried:
print a.replace('\t',"\033[41m\t\033[0m") # 41 = red color
# instead it works (in Linux) for the \n (substituted with a red
space):
print a.replace('\n',"\033[41m \033[0m\n")

Can you help me?
Bye.