Change Details

We're using `shadesDark80` and `shadesDark70` for dark mode, so I figure it made sense to use the corresponding `shadesWhite80` and `shadesWhite70` for light mode. I also think this looks better. Note that `panelSecondaryForeground` is only used in the calendar, as well as the inner tile in `ExistingEthereumAccount`. Meanwhile, `panelSecondaryForegroundBorder` is only used in `RegistrationTile`. Screenshots for all three are in the Test Plan. Depends on D7887

We're using `shadesDark80` and `shadesDark70` for dark mode, so I figure it made sense to use the corresponding `shadesWhite80` and `shadesWhite70` for light mode. I also think this looks better. Note that `panelSecondaryForeground` is only used in the calendar, as well as the inner tile in `ExistingEthereumAccount`. Meanwhile, `panelSecondaryForegroundBorder` is only used for placeholder text in the new registration flow, and the border around a non-selected radio button in `RegistrationTile`. Screenshots for all three are in the Test Plan. Depends on D7887

We're using `shadesDark80` and `shadesDark70` for dark mode, so I figure it made sense to use the corresponding `shadesWhite80` and `shadesWhite70` for light mode. I also think this looks better. Note that `panelSecondaryForeground` is only used in the calendar, as well as the inner tile in `ExistingEthereumAccount`. Meanwhile, `panelSecondaryForegroundBorder` is only used for placeholder text in the new registration flow, and the border around a non-selected radio button in `RegistrationTile`. Screenshots for all three are in the Test Plan. Depends on D7887