Looks like an unstable dye bleed usually caused by high Ph, dyes tend not to bleed on synthetics because they are solution dyed. High Ph on furniture especially on blends with naturals can bleed and can excel with heat ;one should stay under ph of 10 and slightly mist fabric ,too many guys clean fabrics like carpets. They over wet them . Kleenrite makes some great upholstery cleaning products that go on as 10 but self neutralize to 7 in 10 minutes. You may have to re upholster this one. If you have not taken an IICRC Upholstery class I would strongly suggest it.sometimes red can indicate too much acid test ph to see but ref dyes and blue bleed easily from the naturals in the blends. Sometimes there are indicator dyes as well
