I want my custom color rose_color to be applied for background color for \framed inside lmt_text. For fill fullcircle, it works. With predefined colors as green, it works.

\starttext

\startMPcode

color rose_color; rose_color = 1/256(255,204,255);

%not working
draw lmt_text [text ="\framed[background=color,backgroundcolor=rose_color,frame=on, location=low]{a rose box}",];

%working
draw lmt_text [text ="\framed[background=color,backgroundcolor=green,frame=on, location=low]{a green box}",] shifted (1cm,1cm);

%working
fill fullcircle scaled 2cm shifted (0,3cm) withcolor rose_color;

\stopMPcode

\stoptext