Using v.4.1.6

I would like to format different digits of a number differently, e.g., I would like the whole number part to be one color and the part after the decimal point another color; also more involved coloring schemes with more than 2 colors. Sometimes when data is normally integer type and special circumstances arise I will use digits after a decimal point to flag the special circumstances, e.g., 237.002003 might indicate a true value of 237 but with special issue A, type 2, and special issue B, type 3; in such cases I would like the columns www.xxxyyy to have 3 different colors, perhaps with xxx or yyy bold type.

If I color different columns in such way by hand, then the number is converted to text.  All attempts to re-convert the text back to a number cause the special formatting to disappear.

This would be a nice feature to have if it doesn't already exist.  It would be nicer still if it could be implemented with conditional formatting.