AdditiveColorGradient, Corona, and LightTable shader compilation error

It seems recent change to add the alpha transparency component to colors broke shaders on macOS. Trying to load the SampleProject throws:
qt3ds.invalid_operation: Fragment compilation output:: WARNING: 0:4: extension 'GL_ARB_shading_language_420pack' is not supported
qt3ds.invalid_operation: Fragment compilation output:: ERROR: 0:196: Too many arguments to constructor of 'vec4'
qt3ds.invalid_operation: Fragment compilation output:: ERROR: 0:197: Use of undeclared identifier 'vigmixcolor'

Attached image shows the result in the editor (and when run with Slayer runtime).