Shell Programming and Scripting

I have a file like:

Code:

s_20331 803  1  1  5 1:2=0.00000000 1:3=0.00000000 1:4=0.11111111
s_20331 814  1  1  5 1:2=0.00000000 1:3=0.12611607 1:4=0.00000000

I would like to remove the four characters "x:x=" from all columns containing them (in my actual file, there are 15 total columns (i.e. columns 6-20) beginning with "x:x=")
Desired output:

Code:

s_20331 803  1  1  5 0.00000000 0.00000000 0.11111111
s_20331 814  1  1  5 0.00000000 0.12611607 0.00000000

I know I can use cut to remove the first characters of a line, but I'm not sure how to make it apply to only the correct columns.
And I know that I can use

Code:

sed "s/[^=]*=//"

to cut all characters up to and excluding "=" but again, I don't know how to apply it only to the desired columns.

Code:

sed 's/.:.=//g'

The g modifier does multiple substitutions in the line.