Colour: brown to red to mahogany-back to red?

[esmith7713]

OK- my wife is a natural brunette (with gray). she had her hair bleached and dyed red over a year ago and it looked fantastic. she just changed salons and had it colored. it's now more mahogany - not as red as before. is there an easy way to go back to more red? she's hoping not to bleach it again. if so, what would be the recommended steps? thanks in advance!!