Get day of the week ill give you 2000 L

// replace with vectors for other colours if needed.
list days = [<1,1,1>,<1,0,0>,<0,1,0>,<0,0,1>,<1,1,0>,<1,0,1>,<0,1,1>];
integer today;

default
{
   state_entry()
   {
      today = 0;
      llSetColor(llList2Vector(days,today),ALL_SIDES);
      llSetTimerEvent(86400);  //24 hours in seconds
   }
   
   timer()
   {
      today++;
      if ( today == llGetListLength(days) ) today = 0;
      llSetColor(llList2Vector(days,today),ALL_SIDES);
   }
}

// replace with vectors for other colours if needed.
integer DayOfWeek()
{
    string DateUTC = llGetDate();
    integer year = (integer)llGetSubString(DateUTC, 0, 3);
    integer month = (integer)llGetSubString(DateUTC, 5, 6);
    return (year + (year - 1) / 4 - (year - 1) / 100 + (year - 1) / 400
        + llList2Integer( [ 0, 6, 2, 2, 5, 0, 3, 5, 1, 4, 6, 2, 4 ], month)
        + (integer) llGetSubString(DateUTC ,  8,  9)
        + (month>2) * (!(year % 4) - !(year % 100) + !(year % 400))) % 7;
}

//and the colors are even what you requested :P
//it changes colors within 10 min after midnight, and it will be accurate long past we are all dead.
list days = [<1,1,1>,<0,0,1>,<0,1,0>,<1,1,0>,<1,0.5,0.25>,<1,0,0>,<0.5,0,0.5>];
integer today;

default
{
   state_entry()
   {
      today = 0;
      llSetColor(llList2Vector(days, DayOfWeek()),ALL_SIDES);
      llSetTimerEvent(600);
   }
   timer()
   {
      integer a = DayOfWeek();
      if(a != today)
          llSetColor(llList2Vector(days,today=a),ALL_SIDES);
   }
}

// replace with vectors for other colours if needed.
list days = [<1,1,0>,<1,0.75,0.25>,<1,0,0>,<1,0,1>,<1,1,1>,<0,0,1>,<0,1,0>];
integer today;
integer timerevent;
integer firstimeitgottohere;

default
{
   state_entry()
   {
      today = 0;
      timerevent =55; //first day itll check every 55 seconds to see if its midnight
      llSetLinkColor(LINK_SET,llList2Vector(days,today),ALL_SIDES);
     // llSetTimerEvent(2);
      llSetTimerEvent(timerevent);  //24 hours in seconds
      firstimeitgottohere = 0; // sets the day  color to thursdays color of orange
   }
   
   timer()
   {
     float midnight=llGetGMTclock();
     if(midnight <= 60 && firstimeitgottohere == 0){  // if it was midnight less than 60 seconds ago it woll set the timer to 24 hours
         
         timerevent = 86400;
          llSetTimerEvent(timerevent);  //24 hours in seconds
         firstimeitgottohere = firstimeitgottohere +1; //this will count the days from now on but the first time is all we carre about
        }
       
      today++;
        if(timerevent != 86400){
          today = 0; // if its still checking every 55 seconds  then today is the wednesday color
        }
        if(timerevent == 86400){
            if(firstimeitgottohere == 1){    
          today = 1;  
        }
        }
      if ( today == llGetListLength(days) ) today = 0;
      llSetLinkColor(LINK_SET,llList2Vector(days,today),ALL_SIDES);
   }
} 

// replace with vectors for other colours if needed. 
integer DayOfWeekPST() 
{ 
    string DateUTC = llGetDate(); 
    integer year = (integer)llGetSubString(DateUTC, 0, 3); 
    integer month = (integer)llGetSubString(DateUTC, 5, 6); 
    return (year + (year - 1) / 4 - (year - 1) / 100 + (year - 1) / 400 
        + llList2Integer( [ 0, 6, 2, 2, 5, 0, 3, 5, 1, 4, 6, 2, 4 ], month) 
        + (integer) llGetSubString(DateUTC ,  8,  9) 
        + (month>2) * (!(year % 4) - !(year % 100) + !(year % 400))
        - (llGetGMTclock() <  llGetWallclock())) % 7; 
} 

//and the colors are even what you requested :P 
//it changes colors within 10 min after midnight, and it will be accurate long past we are all dead. 
list days = [<1,1,1>,<0,0,1>,<0,1,0>,<1,1,0>,<1,0.5,0.25>,<1,0,0>,<0.5,0,0.5>]; 
integer today; 

default 
{ 
   state_entry() 
   { 
      today = 0; 
      llSetColor(llList2Vector(days, DayOfWeekPST()),ALL_SIDES); 
      llSetTimerEvent(600); 
   } 
   timer() 
   { 
      integer a = DayOfWeekPST(); 
      if(a != today) 
          llSetColor(llList2Vector(days,today=a),ALL_SIDES);   
   } 
}