They’ve been a colorful part of California’s political landscape for decades — Greens, Libertarians, American Independents and members of the Peace and Freedom Party. But after Tuesday’s election, most of them will be all but invisible — and perhaps on their way to extinction. In past years, minor parties held their own primary elections to choose nominees who would go on to compete with Democratic and Republican nominees in general elections. But that’s no longer the case under California’s new “top two” primary system, in which all voters choose from among all candidates of all parties — and only the two candidates who get the most votes advance to November, regardless of party. Because minor party candidates rarely finish in the top two, and it’s now harder for their candidates to get on the primary ballot in the first place, the parties will have little or no presence on the general-election ballot. And in politics, invisibility means oblivion. “It could spell the end of the Peace and Freedom Party,” said party chairman C.T. Weber, 71, of Sacramento. “It’s a shame that democracy is being undermined by this, but that’s the reality if we’re not able to overturn the law.”