Emissive Materials Change Colors Unexpectedly With Increased Values

When multiplying vector 3 (R,G,B) values by a scalar value of increasing quantity the emissive output will begin to change colors. The most unexpected is the blue color that will turn purple while the bloom remains blue.

The color turning white while being multiplied by larger values seems intentional however, there is no documentation to be found even in our internal 4.15 release notes regarding this behavior.

REGRESSION?
Yes

Worked: Binary 4.14.3 CL 3249277
Broken: Binary 4.15 Preview 1 CL 3258144

1. Create a new blank project
2. Create material and add a vector 3 node with the values (0,0,1)
3. Multiply the vector 3 by a scalar parameter (plug into emissive)
4. Compile and apply the material to a mesh in the scene
5. Start increasing the scalar param to about a value of 10

RESULT
The mesh will start blue then fade to purple if you continue it will turn white.

EXPECTED
The mesh stays blue with increased bloom as the emissive gets multiplied by larger values.

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