I compared your regex (called greedy) with a version using the +? nongreedy qualifier, both against your string (where both will give correct results) and a much longer string, where the non-greedy version will match the first 3 codes, and the greedy version will match the first code and the last 2.

$ perl testGreed.pl
Benchmark: running greedyLong, greedyShort, notGreedyLong, notGreedySh
+ort,
each for at least 3 CPU seconds...

greedyLong:  3 wallclock secs ( 3.00 usr +  0.00 sys =  3.00 CPU) @ 42
+264.23/s (n=127004)
greedyShort:  4 wallclock secs ( 3.20 usr +  0.01 sys =  3.21 CPU) @ 8
+8692.45/s (n=284348)
notGreedyLong:  4 wallclock secs ( 3.13 usr +  0.01 sys =  3.14 CPU) @
+ 46018.76/s (n=144729)
notGreedyShort:  3 wallclock secs ( 2.99 usr +  0.01 sys =  3.00 CPU) 
+@ 101593.68/s (n=305289)
                   Rate    greedyLong notGreedyLong   greedyShort notG
+reedyShort

greedyLong      42264/s            --           -8%          -52%     
+      -58%

notGreedyLong   46019/s            9%            --          -48%     
+      -55%

greedyShort     88692/s          110%           93%            --     
+      -13%

notGreedyShort 101594/s          140%          121%           15%     
+        --
[download]

Here's the comparison code:

#!/usr/bin/perl -w

use strict;
use Benchmark qw(cmpthese);

my $i=0;

my $varshort = "xxx:12345 yyy:54321 zzz:13245";

my $varlong = ("$varshort "x120);

sub greedy {
    $_[0]=~m/.+\:(.+?)\s.+\:(.+?)\s.+\:(.+?)/;
}

sub notGreedy {
    $_[0]=~m/.+\:(.+?)\s.+?\:(.+?)\s.+?\:(.+?)/;
}

sub greedyShort {
    greedy($varshort);
}

sub greedyLong {
    greedy($varlong);
}

sub notGreedyShort {
    notGreedy($varshort);
}

sub notGreedyLong {
    notGreedy($varlong);
}

cmpthese(-3,
        {
            greedyShort   => \&greedyShort,
            greedyLong => \&greedyLong,
            notGreedyShort => \&notGreedyShort,
            notGreedyLong => \&notGreedyLong,
        }
     );
[download]