query_string with Exact string match with in double quote does not select specific field for search

[sivamforeverd]

Elasticsearch version (bin/elasticsearch --version):
7.9.3

Plugins installed: []

JVM version (java -version):
JVM: 1.8.0_275

OS version (uname -a if on a Unix-like system):
Linux version 5.4.0-54-generic (buildd@lcy01-amd64-024) (gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)) #60-Ubuntu SMP Fri Nov 6 10:37:59 UTC 2020

Description of the problem including expected versus actual behavior:
When query_string is used for search along with quoted string, the key is not considered properly. Search is initiated across all the keys

Steps to reproduce:

DELETE /test
GET /test
PUT /test
PUT /test/_mapping
{ "properties" : {
"value1" : {
"type" : "text"
},
"value2" : {
"type" : "text"
}
}
}

POST /test/_doc/1
{
"value1":"red small",
"value2":"red2"
}

POST /test/_doc/2
{
"value1":"small",
"value2":"reddd"
}

POST /test/_search
{
"query":{
"query_string": {
"query": "value2:="red small""
}
}
}

** Above search returns doc "1", but it should not, Since we are looking for "red small" in value2 key and no document is available in the index like this

Above scenario applicable for below mapping also

DELETE /test

GET /test
PUT /test
PUT /test/_mapping
{ "properties" : {
"value1" : {
"type" : "keyword"
},
"value2" : {
"type" : "keyword"
}
}
}

"Color:=(red OR blue)" => This query_string searches for red or blue in all fields, not only in Color
"Color:=red OR Color:=blue" => This query_string works as expected, searches only in Color field

[sivamforeverd]

Instead of "Color:=(red OR blue)" should use "Color:(red OR blue)"