awk script help

i have a file which looks like below

001259 HCART TLD 0 215 - 1 569953856 FULL
001405 HCART TLD 0 2 - 3 444650118 FULL/MPX
001473 HCART TLD 0 11 - 1 477960976 FULL/MPX
001484 HCART TLD 0 10 - 1 601812747 FULL/MPX
001498 HCART TLD 0 182 - 3 418481688 FULL/MPX
001500 HCART TLD 0 188 - 1 418912608 FULL/MPX

I want script output to show first col with colon delimited in a row and delete all other columns for example output should be like

001259:001405:001473:001484:001498:001500

cat file.txt | awk '{printf $1":"}' | sed 's/:$//'

Try this:

awk '{s=s?s":"$1:$1}END{print s}' file

I am getting an

awk: syntax error near line 1
awk: illegal statement near line 1

Use nawk or /usr/xpg4/bin/awk on Solaris.

Thanks .