paper-tabs should use theme colors by default

[osechet]

The default background color, text color and selection bar color should be set using the default-theme's values (as it is done with paper-toolbar): --default-primary-color, --text-primary-color, --accent-color. The same should be done with paper-tab: the default paper-tab-ink color should be --accent-color.

[osechet]

As a side note, I would like to say, that the paper-tab-ink does not look good if the --accent-color is used. I think it is better to use the --dark-primary-color as it is done with buttons.

[abdonrd]

Yeah! I proposed this PR: https://github.com/PolymerElements/paper-tabs/pull/55

[osechet]

Reading at the paper-button documentation I noticed the ink color is set as the button's color at 25% opacity (not the dark-primary-color as i suggested earlier). The paper-tab should probably work the same way for consistency.

[motss]

@osechet IMHO, .25 for opacity of the ripple effect on paper-tab seems too low. You won't be able to see the ripple easily and I think at least .5 should be fine. What do you think?

[osechet]

I don't know. My suggestion is based on what I saw in the paper-button doc. If the effect is OK for the button, it should be OK or the tab.