Text: the reflected colors will then only depend on the constructive or destructive interference of the to outgoing rays.

Correct capitalization: The reflected colors will then only depend on the constructive or destructive interference of the to outgoing rays.

Text: send me periodic emails on news, product updates and invitations to events

Correct capitalization: Send me periodic emails on news, product updates and invitations to events

Text: the evening was still light at home after they had eaten their milk porridge.

Correct capitalization: The evening was still light at home after they had eaten their milk porridge.

Text: 2 legislative power gradually taken from the gods

Correct capitalization:
2 Legislative power gradually taken from the gods