I managed today to make the "Reminders" icon pure white after an fail attempt to make spire work on my ipad 2 and saw that i had to format and re-jailbreak to fix it? but that is not the easiest way.
i found a small link witch told a person with the same issue as me to just download just one random file from cydia and it fixed he's problem.
So i did the same, i downloaded a free dreamboard theme of 7 mb, and it actually fixed it! The icon is now back to normal.
Admin, take this tip and make it visible to all with the white icon issue/problem as i had today. It may help them prevent to system restore ipad just for one blank icon
Sent from my iPad 2 wifi 32gb (jailbreaked) using iPF