Colors inside formulas imported from MathType

[Saw]

TL;DR Summary

How to include colors in numbers or letters of equations, esp. when pasted from MathType

I would like to include colors in letters or numbers inside formulas just like I did here with text.
By the way, I use the software MathType to build my formulas and used to be able to paste the equations easily on PhysicsForums, but can't do it lately. Do you know by chance the Copy-and-Paste option that I should choose at MathType so that the equation is readable here?

 

[Saw]

I think I could answer myself.

With MathType (6.9 in my case), the Copy preference is last option "Equation for application or website" and choose Physics Forum in the list.

The copied code unfortunately misses the colors but you can edit it to reinclude them with code, for example, \color{red}{thenumberorletter}, like here:

$$\begin{array}{l} \color{red}{e_x} = (\color{blue}{e_x},0) = (1,0)\\ \color{red}{e_t} = (v\color{blue}{e_x},{e_t}) = (v,1) \end{array}$$

The thing is that, as noted in some threads, the preview functionality works erratically. Apparently you need to reload the page... Bug to be fixed, isn't it?