IPhone change calendar colors

sqlite3 should be installed by Cydia, or from command prompt:

apt-get install sqlite3

Query your current config:

cd /var/mobile/Library/Calendar
sqlite3 Calendar.sqlitedb

On the sqlite prompt:

select store_id,title, external_id_tag,color_r,color_g,color_b from Calendar;

In my case the output is:

1|Default||-1|-1|-1
2|Birthdays||47|141|0
1|Calendar||15|77|140
6|Calendar||15|77|140
11|Tasks|/dav/roland@breedveld.net/Tasks/|245|120|2
11|Calendar|/dav/roland@breedveld.net/Calendar/|132|130|132

Change the colors, on the sqlite prompt:

.header on
update Calendar set color_r=15, color_g=77, color_b=140 where store_id = '6';
update Calendar set color_r=181, color_g=0, color_b=13 where store_id = '11';
.
.exit

Colors should be effective immediatley

RGB Values for the Standard Colors

Red = (181,0,13)
Orange = (229,98,0)
Green = (47,141,0)
Blue = (15,77,140)
Purple = (103,10,108)