If you are using an Apple (iOS) device and would like to change your subscription, please go through the following steps:
Open Settings in your device;
Tap iTunes & App Store;
Tap on your Apple ID: (your email address);
Tap View Apple ID;
Tap on Subscriptions;
Click on the Color by Number subscription;
Select the subscription you want to change it to.
If you are using an Android (Google) device and would like to change your subscription, please first cancel the subscription and then resubscribe by going through the following steps:
On your Android phone or tablet, open the Google Play Store.
Tap Menu Subscriptions.
Tap the subscription you want to change.
Tap Cancel subscription.
Follow the onscreen instructions.
Open the game.
Choose the desired frequency of the subscription.
Confirm the new subscription.
The new subscription will take effect and be charged accordingly after the current period ends.