There is no simple formula for #d4c957, but we have one for color #d5c955, that is similar to #d4c957 by 99.6%.
Color #d5c955 name: soft yellow
Hex #d5c955 or rgb(213,201,85) in RGB space is the tint of yellow. It has hue angle of 54.38 degrees, value = 84 and saturation = 60. #d5c955 can be obtained by mixing 4 colors: 3 drops of yellow, 1 drop of red, 1 drop of cyan, 1 drop of white.
Nearest safe hex - #cccc66. Below you can see the block with #d5c955 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #d5c955 to the mixer and play with it.