RVIZ PointCloud2 Not Displaying Colors

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Regardless of the settings I use in RVIZ for my PointCloud2, I'm only seeing gray points. It also seems as if the cloud shapes do not update as well. Screenshot as follows:

I've love to get the AxisColor option working on my Z axis, but as you can see, not even the FlatColor option is working.

I'm using Ros Melodic on Ubuntu 18.04. I used apt to install the rviz libraries:

• ros-melodic-librviz-tutorial/bionic,now 0.10.3-0bionic.20190808.224910 amd64 [installed,automatic]
• ros-melodic-rqt-rviz/bionic,now 0.6.0-0bionic.20190808.224756 amd64 [installed,automatic]
• ros-melodic-rviz/bionic,now 1.13.3-0bionic.20190808.210904 amd64 [installed]
• ros-melodic-rviz-imu-plugin/bionic,now 1.2.1-1bionic.20190808.224935 amd64 [installed]
• ros-melodic-rviz-plugin-tutorials/bionic,now 0.10.3-0bionic.20190808.224933 amd64 [installed,automatic]
• ros-melodic-rviz-python-tutorial/bionic,now 0.10.3-0bionic.20190808.224929 amd64 [installed,automatic]
• ros-melodic-rviz-visual-tools/bionic,now 3.7.0-0bionic.20190808.224259 amd64 [installed]

Any help appreciated.