The #white option you added is correct. Now to make a shortcut for this is not as simple, as this function has 6 options, so you would need 6 different Macros (asCopy true/false and 3 materials) or 1 Macro with a popup window where you can select the options you want.
Here is a MacroScript that will open a popup dialog. You will find it in the Customize menu under Category “Medit Tools”. The Action name is “Assign VRay Material”
macroScript AssignVRayMaterial
category:"Medit Tools"
tooltip:"Assign VRay Material"
(
rollout ro_assign_material "Assign VRay Material" width:120 height:112
(
button bt_default "Default" pos:[8,8] width:104 height:24
button bt_chrome "Chrome" pos:[8,32] width:104 height:24
button bt_white "White" pos:[8,56] width:104 height:24
checkbox chk_asCopy "As Copy" pos:[8,88] width:104 height:16
local AssignMat
fn AssignMat asCopy:false type:#default =
(
if selection.count > 0 do
(
case type of
(
#chrome: mat = VRayMtl Diffuse:[0,0,0] Reflection:[229,229,229]
#default: mat = VRayMtl Diffuse:[128,128,128]
#white: mat = VRayMtl Diffuse:[220,220,220]
)
for o in selection do o.Material = if asCopy then copy mat else mat
)
)
on bt_default pressed do AssignMat asCopy:(chk_asCopy.checked) type:#default
on bt_chrome pressed do AssignMat asCopy:(chk_asCopy.checked) type:#chrome
on bt_white pressed do AssignMat asCopy:(chk_asCopy.checked) type:#white
)
createdialog ro_assign_material style:#(#style_titlebar, #style_toolwindow, #style_sysmenu)
)




