What is the value of a red stamped silver dollar?

Your question isn't clear.

If you're referring to a silver dollar coin, none would have been made with any kind of red marking on them; it was almost certainly added after the coin was made. Depending on what the "red" is - paint, varnish, chemical damage, etc. - the coin's value could be adversely affected. It would have to be examined in person to be sure.

If on the other hand you're referring to a paper billwith a red seal, what you have is an obsolete form of paper money called a United States Note rather than a silver certificate. In this case please post a new and separate question with its seal color, date, and whether there's a small letter next to / under the date. That information is important when determining a value. You don't need to include the serial number, though.

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US Notes were printed from 1862 until 1971, although the last ones were dated 1966. They were similar to Federal Reserve Notes except that they were issued directly by the government rather than through the central banking system. Starting in 1928, the seal color was changed to red as a unique identifier. Even though US Notes were functionally identical to green-seal Federal Reserve Notes they continued to be issued for several more decades. The Treasury finally discontinued them to reduce printing and accounting costs.

Silver certificates were a different type of paper money backed one-for-one with silver on deposit in the Treasury. Starting in 1928 all silver certificates were identified by blue seals. Silver certificates were discontinued in the early 1960s when the price of silver was deregulated.