firstly, cocoa butter must be tempered before splattered.
This might work: pour a little bit of chocolate in the mold, tap it/vibrate until every pcs has a a thin layer of chocolate in it. Then mold the rest of the chocolate. The chocolate might be too cold too.
Thank you everyone for your comments. I'm not certain what the temperature of the cocoa butter was, I warmed the bottle and shook it up to "temper it." The cocoa butter solidified in the mold after about 15 minutes, then I poured 32C tempered dark chocolate into the mold.
Could the colored cocoa butter be out of temper? I didn't have a problem with it before, so I'm wondering if somewhere along the way, all the continued melting and shaking of the cocoa butter bottle has brought it out of temper?
Although, if the cocoa butter is out of temper, I don't know why most of it releases without a problem. Seems like if it is not in temper, then none of it should release.
There could be a couple of of problems here. The splatters of cocoa butter might be too thick. Your molds would release without problems in the areas with it is not too thick. Your cocoa butter may be out of temper. If you melted all of the cocoa butter out (with nothing solid left in the container) it could be out of temper and simply shaking it will not temper it. If it is all melted out you need to re-temper as you would chocolate. Also, remember that, like chocolate, cocoa butter can be over tempered (over crystalized). I am no expert in working with colored cocoa butter but keep practicing and you'll figure out what methods work best for you.
Along with watching the temper of your cocoa butter, also look at the temperature of your molds. Try to warm them up to within a degrees or two of your temper. If too cold, even a good temper can be ruined, especially since you have a thin coat.
When tempering cocoa butter watch the temperature. For chocolates, rule of thumb is the more other fats/oils in the chocolate, the lower the tempering temperature, with dark being higher than milk, and milk higher than white. A gianduja tempers down to room temp. You would think then that pure cocoa butter would be the highest, but it's lower. Reason here is you can't just look at the fat(s) in your system, but other solids. With pure cocoa butter you don't have the sugar/cocoa particulates to help induce seeding.
I've had a lot of luck using your "shake it in the bottle" tempering. I warm the bottle in hot water until about half is melted. This works better than a microwave since hot water melts outside to in, leaving center cool and hard. I get the melted portion to about 105F, but still that solid center. Then I shake it until the solid center cools down the melted portion to tempering temp. The seed coming from the unmelted center. Didn't take much practice to get it working consistent.