I propose a new attribute "indent" for <math> tag. Its value should be ordinary numbers =>0, default value = 0. If value==0 then the formula will be displayed inline in the text. If value>0, the formula will be displayed on a new line (not in a new paragraph!), properly indented.

A colon (:) is used very often for indentation of the math formula. Since the colon should be actually used only in definition lists (see T6521), this enhancement should help to change this behaviour.